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linux/net/mac80211/tx.c

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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>
#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/ieee80211_radiotap.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "led.h"
#include "mesh.h"
#include "wep.h"
#include "wpa.h"
#include "wme.h"
#include "rate.h"
#define IEEE80211_TX_OK 0
#define IEEE80211_TX_AGAIN 1
#define IEEE80211_TX_PENDING 2
/* misc utils */
static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
int next_frag_len)
{
int rate, mrate, erp, dur, i;
struct ieee80211_rate *txrate;
struct ieee80211_local *local = tx->local;
struct ieee80211_supported_band *sband;
struct ieee80211_hdr *hdr;
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;
sband = local->hw.wiphy->bands[tx->channel->band];
txrate = &sband->bitrates[info->control.rates[0].idx];
erp = txrate->flags & IEEE80211_RATE_ERP_G;
/*
* 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
*/
hdr = (struct ieee80211_hdr *)tx->skb->data;
if (ieee80211_is_ctl(hdr->frame_control)) {
/* TODO: These control frames are not currently sent by
* mac80211, but should they be implemented, this function
* needs to be updated to support duration field calculation.
*
* RTS: time needed to transmit pending data/mgmt frame plus
* one CTS frame plus one ACK frame plus 3 x SIFS
* CTS: duration of immediately previous RTS minus time
* required to transmit CTS and its SIFS
* ACK: 0 if immediately previous directed data/mgmt had
* more=0, with more=1 duration in ACK frame is duration
* from previous frame minus time needed to transmit ACK
* and its SIFS
* PS Poll: BIT(15) | BIT(14) | aid
*/
return 0;
}
/* data/mgmt */
if (0 /* FIX: data/mgmt during CFP */)
return cpu_to_le16(32768);
if (group_addr) /* Group address as the destination - no ACK */
return 0;
/* Individual destination address:
* IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
* CTS and ACK frames shall be transmitted using the highest rate in
* basic rate set that is less than or equal to the rate of the
* immediately previous frame and that is using the same modulation
* (CCK or OFDM). If no basic rate set matches with these requirements,
* the highest mandatory rate of the PHY that is less than or equal to
* the rate of the previous frame is used.
* Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
*/
rate = -1;
/* 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];
if (r->bitrate > txrate->bitrate)
break;
if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
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;
}
}
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,
tx->sdata->vif.bss_conf.use_short_preamble);
if (next_frag_len) {
/* Frame is fragmented: duration increases with time needed to
* transmit next fragment plus ACK and 2 x SIFS. */
dur *= 2; /* ACK + SIFS */
/* next fragment */
dur += ieee80211_frame_duration(local, next_frag_len,
txrate->bitrate, erp,
tx->sdata->vif.bss_conf.use_short_preamble);
}
return cpu_to_le16(dur);
}
static int inline is_ieee80211_device(struct ieee80211_local *local,
struct net_device *dev)
{
return local == wdev_priv(dev->ieee80211_ptr);
}
/* tx handlers */
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
u32 sta_flags;
if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
return TX_CONTINUE;
if (unlikely(tx->local->sw_scanning) &&
!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
*/
return TX_DROP;
if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
return TX_CONTINUE;
if (tx->flags & IEEE80211_TX_PS_BUFFERED)
return TX_CONTINUE;
sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
ieee80211_is_data(hdr->frame_control))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: dropped data frame to not "
"associated station %pM\n",
tx->dev->name, hdr->addr1);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
return TX_DROP;
}
} else {
if (unlikely(ieee80211_is_data(hdr->frame_control) &&
tx->local->num_sta == 0 &&
tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
/*
* No associated STAs - no need to send multicast
* frames.
*/
return TX_DROP;
}
return TX_CONTINUE;
}
return TX_CONTINUE;
}
/* This function is called whenever the AP is about to exceed the maximum limit
* of buffered frames for power saving STAs. This situation should not really
* happen often during normal operation, so dropping the oldest buffered packet
* from each queue should be OK to make some room for new frames. */
static void purge_old_ps_buffers(struct ieee80211_local *local)
{
int total = 0, purged = 0;
struct sk_buff *skb;
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
/*
* virtual interfaces are protected by RCU
*/
rcu_read_lock();
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
struct ieee80211_if_ap *ap;
if (sdata->vif.type != NL80211_IFTYPE_AP)
continue;
ap = &sdata->u.ap;
skb = skb_dequeue(&ap->ps_bc_buf);
if (skb) {
purged++;
dev_kfree_skb(skb);
}
total += skb_queue_len(&ap->ps_bc_buf);
}
list_for_each_entry_rcu(sta, &local->sta_list, list) {
skb = skb_dequeue(&sta->ps_tx_buf);
if (skb) {
purged++;
dev_kfree_skb(skb);
}
total += skb_queue_len(&sta->ps_tx_buf);
}
rcu_read_unlock();
local->total_ps_buffered = total;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
wiphy_name(local->hw.wiphy), purged);
#endif
}
static ieee80211_tx_result
ieee80211_tx_h_multicast_ps_buf(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;
/*
* 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.
*/
/* powersaving STAs only in AP/VLAN mode */
if (!tx->sdata->bss)
return TX_CONTINUE;
/* no buffering for ordered frames */
if (ieee80211_has_order(hdr->frame_control))
return TX_CONTINUE;
/* no stations in PS mode */
if (!atomic_read(&tx->sdata->bss->num_sta_ps))
return TX_CONTINUE;
/* buffered in mac80211 */
if (tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) {
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) {
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: BC TX buffer full - "
"dropping the oldest frame\n",
tx->dev->name);
}
#endif
dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
} else
tx->local->total_ps_buffered++;
skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
return TX_QUEUED;
}
/* buffered in hardware */
info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
return TX_CONTINUE;
}
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;
}
static ieee80211_tx_result
ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
{
struct sta_info *sta = tx->sta;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
u32 staflags;
if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control)))
return TX_CONTINUE;
staflags = get_sta_flags(sta);
if (unlikely((staflags & WLAN_STA_PS) &&
!(staflags & WLAN_STA_PSPOLL))) {
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
"before %d)\n",
sta->sta.addr, sta->sta.aid,
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);
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: STA %pM TX "
"buffer full - dropping oldest frame\n",
tx->dev->name, sta->sta.addr);
}
#endif
dev_kfree_skb(old);
} else
tx->local->total_ps_buffered++;
/* Queue frame to be sent after STA sends an PS Poll frame */
if (skb_queue_empty(&sta->ps_tx_buf))
sta_info_set_tim_bit(sta);
info->control.jiffies = jiffies;
skb_queue_tail(&sta->ps_tx_buf, tx->skb);
return TX_QUEUED;
}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
else if (unlikely(test_sta_flags(sta, WLAN_STA_PS))) {
printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
"set -> send frame\n", tx->dev->name,
sta->sta.addr);
}
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
clear_sta_flags(sta, WLAN_STA_PSPOLL);
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
{
if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
return TX_CONTINUE;
if (tx->flags & IEEE80211_TX_UNICAST)
return ieee80211_tx_h_unicast_ps_buf(tx);
else
return ieee80211_tx_h_multicast_ps_buf(tx);
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
{
struct ieee80211_key *key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
if (unlikely(tx->skb->do_not_encrypt))
tx->key = NULL;
else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
tx->key = key;
else if (ieee80211_is_mgmt(hdr->frame_control) &&
(key = rcu_dereference(tx->sdata->default_mgmt_key)))
tx->key = key;
else if ((key = rcu_dereference(tx->sdata->default_key)))
tx->key = key;
else if (tx->sdata->drop_unencrypted &&
(tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) &&
!(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)))) {
I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
return TX_DROP;
} else
tx->key = NULL;
if (tx->key) {
tx->key->tx_rx_count++;
/* TODO: add threshold stuff again */
switch (tx->key->conf.alg) {
case ALG_WEP:
if (ieee80211_is_auth(hdr->frame_control))
break;
case ALG_TKIP:
if (!ieee80211_is_data_present(hdr->frame_control))
tx->key = NULL;
break;
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;
case ALG_AES_CMAC:
if (!ieee80211_is_mgmt(hdr->frame_control))
tx->key = NULL;
break;
}
}
if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
tx->skb->do_not_encrypt = 1;
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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;
memset(&txrc, 0, sizeof(txrc));
sband = tx->local->hw.wiphy->bands[tx->channel->band];
len = min_t(int, tx->skb->len + FCS_LEN,
tx->local->fragmentation_threshold);
/* 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 */
if (tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD &&
len > tx->local->rts_threshold) {
txrc.rts = rts = true;
}
/*
* 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;
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];
if (tx->sta)
tx->sta->last_tx_rate = txrc.reported_rate;
if (unlikely(!info->control.rates[0].count))
info->control.rates[0].count = 1;
if (is_multicast_ether_addr(hdr->addr1)) {
/*
* XXX: verify the rate is in the basic rateset
*/
return TX_CONTINUE;
}
/*
* 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;
}
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;
}
/*
* 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;
}
/* set up RTS protection if desired */
if (rts)
info->control.rates[i].flags |=
IEEE80211_TX_RC_USE_RTS_CTS;
/* RC is busted */
if (WARN_ON_ONCE(info->control.rates[i].idx >=
sband->n_bitrates)) {
info->control.rates[i].idx = -1;
continue;
}
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;
}
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);
if (tx->sta)
info->control.sta = &tx->sta->sta;
return TX_CONTINUE;
}
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;
/*
* 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;
if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
return TX_CONTINUE;
if (ieee80211_hdrlen(hdr->frame_control) < 24)
return TX_CONTINUE;
/*
* Anything but QoS data that has a sequence number field
* (is long enough) gets a sequence number from the global
* counter.
*/
if (!ieee80211_is_data_qos(hdr->frame_control)) {
/* driver should assign sequence number */
info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
/* 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;
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;
}
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;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (void *)skb->data;
int frag_threshold = tx->local->fragmentation_threshold;
int hdrlen;
int fragnum;
if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
return TX_CONTINUE;
/*
* Warn when submitting a fragmented A-MPDU frame and drop it.
* This scenario is handled in __ieee80211_tx_prepare but extra
* caution taken here as fragmented ampdu may cause Tx stop.
*/
if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
return TX_DROP;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
/* internal error, why is TX_FRAGMENTED set? */
if (WARN_ON(skb->len <= frag_threshold))
return TX_DROP;
/*
* 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;
/* update duration/seq/flags of fragments */
fragnum = 0;
do {
int next_len;
const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
hdr = (void *)skb->data;
info = IEEE80211_SKB_CB(skb);
if (skb->next) {
hdr->frame_control |= morefrags;
next_len = skb->next->len;
/*
* 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;
} else {
hdr->frame_control &= ~morefrags;
next_len = 0;
}
hdr->duration_id = ieee80211_duration(tx, 0, next_len);
hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
fragnum++;
} while ((skb = skb->next));
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
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);
case ALG_AES_CMAC:
return ieee80211_crypto_aes_cmac_encrypt(tx);
}
/* not reached */
WARN_ON(1);
return TX_DROP;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
struct ieee80211_hdr *hdr;
int next_len;
bool group_addr;
do {
hdr = (void *) skb->data;
next_len = skb->next ? skb->next->len : 0;
group_addr = is_multicast_ether_addr(hdr->addr1);
hdr->duration_id =
ieee80211_duration(tx, group_addr, next_len);
} while ((skb = skb->next));
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
if (!tx->sta)
return TX_CONTINUE;
tx->sta->tx_packets++;
do {
tx->sta->tx_fragments++;
tx->sta->tx_bytes += skb->len;
} while ((skb = skb->next));
return TX_CONTINUE;
}
/* actual transmit path */
/*
* deal with packet injection down monitor interface
* with Radiotap Header -- only called for monitor mode interface
*/
static ieee80211_tx_result
__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
struct sk_buff *skb)
{
/*
* this is the moment to interpret and discard the radiotap header that
* must be at the start of the packet injected in Monitor mode
*
* Need to take some care with endian-ness since radiotap
* args are little-endian
*/
struct ieee80211_radiotap_iterator iterator;
struct ieee80211_radiotap_header *rthdr =
(struct ieee80211_radiotap_header *) skb->data;
struct ieee80211_supported_band *sband;
int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
sband = tx->local->hw.wiphy->bands[tx->channel->band];
skb->do_not_encrypt = 1;
tx->flags &= ~IEEE80211_TX_FRAGMENTED;
/*
* 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))
return TX_DROP;
skb_trim(skb, skb->len - FCS_LEN);
}
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
tx->skb->do_not_encrypt = 0;
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
tx->flags |= IEEE80211_TX_FRAGMENTED;
break;
/*
* Please update the file
* Documentation/networking/mac80211-injection.txt
* when parsing new fields here.
*/
default:
break;
}
}
if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
return TX_DROP;
/*
* remove the radiotap header
* iterator->max_length was sanity-checked against
* skb->len by iterator init
*/
skb_pull(skb, iterator.max_length);
return TX_CONTINUE;
}
/*
* initialises @tx
*/
static ieee80211_tx_result
__ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
struct sk_buff *skb,
struct net_device *dev)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hdr *hdr;
struct ieee80211_sub_if_data *sdata;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen, tid;
u8 *qc, *state;
bool queued = false;
memset(tx, 0, sizeof(*tx));
tx->skb = skb;
tx->dev = dev; /* use original interface */
tx->local = local;
tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
tx->channel = local->hw.conf.channel;
/*
* Set this flag (used below to indicate "automatic fragmentation"),
* it will be cleared/left by radiotap as desired.
*/
tx->flags |= IEEE80211_TX_FRAGMENTED;
/* process and remove the injection radiotap header */
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
return TX_DROP;
/*
* __ieee80211_parse_tx_radiotap has now removed
* the radiotap header that was present and pre-filled
* 'tx' with tx control information.
*/
}
/*
* 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;
hdr = (struct ieee80211_hdr *) skb->data;
tx->sta = sta_info_get(local, hdr->addr1);
if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
unsigned long flags;
struct tid_ampdu_tx *tid_tx;
qc = ieee80211_get_qos_ctl(hdr);
tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
spin_lock_irqsave(&tx->sta->lock, flags);
/*
* 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];
state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
if (*state == HT_AGG_STATE_OPERATIONAL) {
info->flags |= IEEE80211_TX_CTL_AMPDU;
} 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);
}
spin_unlock_irqrestore(&tx->sta->lock, flags);
if (unlikely(queued))
return TX_QUEUED;
}
if (is_multicast_ether_addr(hdr->addr1)) {
tx->flags &= ~IEEE80211_TX_UNICAST;
info->flags |= IEEE80211_TX_CTL_NO_ACK;
} else {
tx->flags |= IEEE80211_TX_UNICAST;
info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
}
if (tx->flags & IEEE80211_TX_FRAGMENTED) {
if ((tx->flags & IEEE80211_TX_UNICAST) &&
skb->len + FCS_LEN > local->fragmentation_threshold &&
!(info->flags & IEEE80211_TX_CTL_AMPDU))
tx->flags |= IEEE80211_TX_FRAGMENTED;
else
tx->flags &= ~IEEE80211_TX_FRAGMENTED;
}
if (!tx->sta)
info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
tx->ethertype = (pos[0] << 8) | pos[1];
}
info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
return TX_CONTINUE;
}
/*
* NB: @tx is uninitialised when passed in here
*/
static int ieee80211_tx_prepare(struct ieee80211_local *local,
struct ieee80211_tx_data *tx,
struct sk_buff *skb)
{
struct net_device *dev;
dev = dev_get_by_index(&init_net, skb->iif);
if (unlikely(dev && !is_ieee80211_device(local, dev))) {
dev_put(dev);
dev = NULL;
}
if (unlikely(!dev))
return -ENODEV;
/*
* initialises tx with control
*
* return value is safe to ignore here because this function
* can only be invoked for multicast frames
*
* XXX: clean up
*/
__ieee80211_tx_prepare(tx, skb, dev);
dev_put(dev);
return 0;
}
static int __ieee80211_tx(struct ieee80211_local *local,
struct sk_buff **skbp,
struct sta_info *sta)
{
struct sk_buff *skb = *skbp, *next;
struct ieee80211_tx_info *info;
int ret, len;
bool fragm = false;
local->mdev->trans_start = jiffies;
while (skb) {
if (ieee80211_queue_stopped(&local->hw,
skb_get_queue_mapping(skb)))
return IEEE80211_TX_PENDING;
info = IEEE80211_SKB_CB(skb);
if (fragm)
info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
IEEE80211_TX_CTL_FIRST_FRAGMENT);
next = skb->next;
len = skb->len;
ret = local->ops->tx(local_to_hw(local), skb);
if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
dev_kfree_skb(skb);
ret = NETDEV_TX_OK;
}
if (ret != NETDEV_TX_OK)
return IEEE80211_TX_AGAIN;
*skbp = skb = next;
ieee80211_led_tx(local, 1);
fragm = true;
}
return IEEE80211_TX_OK;
}
/*
* 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;
#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)
CALL_TXH(ieee80211_tx_h_sequence)
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
txh_done:
if (unlikely(res == TX_DROP)) {
I802_DEBUG_INC(tx->local->tx_handlers_drop);
while (skb) {
struct sk_buff *next;
next = skb->next;
dev_kfree_skb(skb);
skb = next;
}
return -1;
} else if (unlikely(res == TX_QUEUED)) {
I802_DEBUG_INC(tx->local->tx_handlers_queued);
return -1;
}
return 0;
}
static void ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
bool txpending)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
struct ieee80211_tx_data tx;
ieee80211_tx_result res_prepare;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct sk_buff *next;
unsigned long flags;
int ret, retries;
u16 queue;
queue = skb_get_queue_mapping(skb);
WARN_ON(!txpending && !skb_queue_empty(&local->pending[queue]));
if (unlikely(skb->len < 10)) {
dev_kfree_skb(skb);
return;
}
rcu_read_lock();
/* initialises tx */
res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
if (unlikely(res_prepare == TX_DROP)) {
dev_kfree_skb(skb);
rcu_read_unlock();
return;
} else if (unlikely(res_prepare == TX_QUEUED)) {
rcu_read_unlock();
return;
}
sta = tx.sta;
tx.channel = local->hw.conf.channel;
info->band = tx.channel->band;
if (invoke_tx_handlers(&tx))
goto out;
retries = 0;
retry:
ret = __ieee80211_tx(local, &tx.skb, tx.sta);
switch (ret) {
case IEEE80211_TX_OK:
break;
case IEEE80211_TX_AGAIN:
/*
* 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.
*/
if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
goto drop;
/* fall through */
case IEEE80211_TX_PENDING:
skb = tx.skb;
spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
if (__netif_subqueue_stopped(local->mdev, queue)) {
do {
next = skb->next;
skb->next = NULL;
if (unlikely(txpending))
skb_queue_head(&local->pending[queue],
skb);
else
skb_queue_tail(&local->pending[queue],
skb);
} 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;
goto retry;
}
}
out:
rcu_read_unlock();
return;
drop:
rcu_read_unlock();
skb = tx.skb;
while (skb) {
next = skb->next;
dev_kfree_skb(skb);
skb = next;
}
}
/* device xmit handlers */
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;
}
int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ieee80211_master_priv *mpriv = netdev_priv(dev);
struct ieee80211_local *local = mpriv->local;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct net_device *odev = NULL;
struct ieee80211_sub_if_data *osdata;
int headroom;
bool may_encrypt;
enum {
NOT_MONITOR,
FOUND_SDATA,
UNKNOWN_ADDRESS,
} monitor_iface = NOT_MONITOR;
if (skb->iif)
odev = dev_get_by_index(&init_net, skb->iif);
if (unlikely(odev && !is_ieee80211_device(local, odev))) {
dev_put(odev);
odev = NULL;
}
if (unlikely(!odev)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
"originating device\n", dev->name);
#endif
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
local->hw.conf.dynamic_ps_timeout > 0) {
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 +
msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
}
memset(info, 0, sizeof(*info));
info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
osdata = IEEE80211_DEV_TO_SUB_IF(odev);
if (ieee80211_vif_is_mesh(&osdata->vif) &&
ieee80211_is_data(hdr->frame_control)) {
if (is_multicast_ether_addr(hdr->addr3))
memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
else
if (mesh_nexthop_lookup(skb, osdata)) {
dev_put(odev);
return NETDEV_TX_OK;
}
if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
fwded_frames);
} 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;
if (sdata->vif.type != NL80211_IFTYPE_AP)
continue;
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();
}
}
may_encrypt = !skb->do_not_encrypt;
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);
return NETDEV_TX_OK;
}
if (osdata->vif.type == NL80211_IFTYPE_AP_VLAN)
osdata = container_of(osdata->bss,
struct ieee80211_sub_if_data,
u.ap);
if (likely(monitor_iface != UNKNOWN_ADDRESS))
info->control.vif = &osdata->vif;
ieee80211_tx(odev, skb, false);
dev_put(odev);
return NETDEV_TX_OK;
}
int ieee80211_monitor_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_channel *chan = local->hw.conf.channel;
struct ieee80211_radiotap_header *prthdr =
(struct ieee80211_radiotap_header *)skb->data;
u16 len_rthdr;
/*
* 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;
/* 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 */
skb->dev = local->mdev;
/* needed because we set skb device to master */
skb->iif = dev->ifindex;
/* sometimes we do encrypt injected frames, will be fixed
* up in radiotap parser if not wanted */
skb->do_not_encrypt = 0;
/*
* 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
*/
skb_set_mac_header(skb, len_rthdr);
/*
* 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
*/
skb_set_network_header(skb, len_rthdr);
skb_set_transport_header(skb, len_rthdr);
/* pass the radiotap header up to the next stage intact */
dev_queue_xmit(skb);
return NETDEV_TX_OK;
fail:
dev_kfree_skb(skb);
return NETDEV_TX_OK; /* meaning, we dealt with the skb */
}
/**
* ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
* subinterfaces (wlan#, WDS, and VLAN interfaces)
* @skb: packet to be sent
* @dev: incoming interface
*
* Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
* not be freed, and caller is responsible for either retrying later or freeing
* skb).
*
* This function takes in an Ethernet header and encapsulates it with suitable
* IEEE 802.11 header based on which interface the packet is coming in. The
* encapsulated packet will then be passed to master interface, wlan#.11, for
* transmission (through low-level driver).
*/
int ieee80211_subif_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct ieee80211_local *local = sdata->local;
int ret = 1, head_need;
u16 ethertype, hdrlen, meshhdrlen = 0;
__le16 fc;
struct ieee80211_hdr hdr;
struct ieee80211s_hdr mesh_hdr;
const u8 *encaps_data;
int encaps_len, skip_header_bytes;
int nh_pos, h_pos;
struct sta_info *sta;
u32 sta_flags = 0;
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];
fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_AP_VLAN:
fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
/* DA BSSID SA */
memcpy(hdr.addr1, skb->data, ETH_ALEN);
memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
hdrlen = 24;
break;
case NL80211_IFTYPE_WDS:
fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
/* RA TA DA SA */
memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
memcpy(hdr.addr3, skb->data, ETH_ALEN);
memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
hdrlen = 30;
break;
#ifdef CONFIG_MAC80211_MESH
case NL80211_IFTYPE_MESH_POINT:
fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
/* Do not send frames with mesh_ttl == 0 */
sdata->u.mesh.mshstats.dropped_frames_ttl++;
ret = 0;
goto fail;
}
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;
}
hdrlen = 30;
break;
#endif
case NL80211_IFTYPE_STATION:
fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
/* BSSID SA DA */
memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
memcpy(hdr.addr3, skb->data, ETH_ALEN);
hdrlen = 24;
break;
case NL80211_IFTYPE_ADHOC:
/* DA SA BSSID */
memcpy(hdr.addr1, skb->data, ETH_ALEN);
memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
hdrlen = 24;
break;
default:
ret = 0;
goto fail;
}
/*
* 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)) {
rcu_read_lock();
sta = sta_info_get(local, hdr.addr1);
if (sta)
sta_flags = get_sta_flags(sta);
rcu_read_unlock();
}
/* receiver and we are QoS enabled, use a QoS type frame */
if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
hdrlen += 2;
}
/*
* Drop unicast frames to unauthorised stations unless they are
* EAPOL frames from the local station.
*/
if (!ieee80211_vif_is_mesh(&sdata->vif) &&
unlikely(!is_multicast_ether_addr(hdr.addr1) &&
!(sta_flags & WLAN_STA_AUTHORIZED) &&
!(ethertype == ETH_P_PAE &&
compare_ether_addr(dev->dev_addr,
skb->data + ETH_ALEN) == 0))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: dropped frame to %pM"
" (unauthorized port)\n", dev->name,
hdr.addr1);
#endif
I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
ret = 0;
goto fail;
}
hdr.frame_control = fc;
hdr.duration_id = 0;
hdr.seq_ctrl = 0;
skip_header_bytes = ETH_HLEN;
if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
encaps_data = bridge_tunnel_header;
encaps_len = sizeof(bridge_tunnel_header);
skip_header_bytes -= 2;
} else if (ethertype >= 0x600) {
encaps_data = rfc1042_header;
encaps_len = sizeof(rfc1042_header);
skip_header_bytes -= 2;
} else {
encaps_data = NULL;
encaps_len = 0;
}
skb_pull(skb, skip_header_bytes);
nh_pos -= skip_header_bytes;
h_pos -= skip_header_bytes;
head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
/*
* 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.
*/
if (head_need > 0 || skb_cloned(skb)) {
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))
goto fail;
}
if (encaps_data) {
memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
nh_pos += encaps_len;
h_pos += encaps_len;
}
if (meshhdrlen > 0) {
memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
nh_pos += meshhdrlen;
h_pos += meshhdrlen;
}
if (ieee80211_is_data_qos(fc)) {
__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);
nh_pos += hdrlen;
h_pos += hdrlen;
skb->iif = dev->ifindex;
skb->dev = local->mdev;
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
/* Update skb pointers to various headers since this modified frame
* is going to go through Linux networking code that may potentially
* need things like pointer to IP header. */
skb_set_mac_header(skb, 0);
skb_set_network_header(skb, nh_pos);
skb_set_transport_header(skb, h_pos);
dev->trans_start = jiffies;
dev_queue_xmit(skb);
return 0;
fail:
if (!ret)
dev_kfree_skb(skb);
return ret;
}
/*
* ieee80211_clear_tx_pending may not be called in a context where
* it is possible that it packets could come in again.
*/
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
int i;
for (i = 0; i < local->hw.queues; i++)
skb_queue_purge(&local->pending[i]);
}
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;
}
/*
* Transmit all pending packets. Called from tasklet, locks master device
* TX lock so that no new packets can come in.
*/
void ieee80211_tx_pending(unsigned long data)
{
struct ieee80211_local *local = (struct ieee80211_local *)data;
struct net_device *dev = local->mdev;
unsigned long flags;
int i;
bool next;
rcu_read_lock();
netif_tx_lock_bh(dev);
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)
continue;
/*
* 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
*/
netif_start_subqueue(local->mdev, i);
while (!skb_queue_empty(&local->pending[i])) {
struct sk_buff *skb = skb_dequeue(&local->pending[i]);
if (!ieee80211_tx_pending_skb(local, skb)) {
skb_queue_head(&local->pending[i], skb);
break;
}
}
/* 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);
}
netif_tx_unlock_bh(dev);
rcu_read_unlock();
}
/* functions for drivers to get certain frames */
static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
struct sk_buff *skb,
struct beacon_data *beacon)
{
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)
bss->dtim_count = beacon->dtim_period - 1;
else
bss->dtim_count--;
tim = pos = (u8 *) skb_put(skb, 6);
*pos++ = WLAN_EID_TIM;
*pos++ = 4;
*pos++ = bss->dtim_count;
*pos++ = beacon->dtim_period;
if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
aid0 = 1;
if (have_bits) {
/* Find largest even number N1 so that bits numbered 1 through
* (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
* (N2 + 1) x 8 through 2007 are 0. */
n1 = 0;
for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
if (bss->tim[i]) {
n1 = i & 0xfe;
break;
}
}
n2 = n1;
for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
if (bss->tim[i]) {
n2 = i;
break;
}
}
/* Bitmap control */
*pos++ = n1 | aid0;
/* Part Virt Bitmap */
memcpy(pos, bss->tim + n1, n2 - n1 + 1);
tim[1] = n2 - n1 + 4;
skb_put(skb, n2 - n1);
} else {
*pos++ = aid0; /* Bitmap control */
*pos++ = 0; /* Part Virt Bitmap */
}
}
struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
struct ieee80211_vif *vif)
{
struct ieee80211_local *local = hw_to_local(hw);
struct sk_buff *skb = NULL;
struct ieee80211_tx_info *info;
struct ieee80211_sub_if_data *sdata = NULL;
struct ieee80211_if_ap *ap = NULL;
struct beacon_data *beacon;
struct ieee80211_supported_band *sband;
enum ieee80211_band band = local->hw.conf.channel->band;
sband = local->hw.wiphy->bands[band];
rcu_read_lock();
sdata = vif_to_sdata(vif);
if (sdata->vif.type == NL80211_IFTYPE_AP) {
ap = &sdata->u.ap;
beacon = rcu_dereference(ap->beacon);
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;
skb_reserve(skb, local->tx_headroom);
memcpy(skb_put(skb, beacon->head_len), beacon->head,
beacon->head_len);
/*
* 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) {
ieee80211_beacon_add_tim(ap, skb, beacon);
} else {
unsigned long flags;
spin_lock_irqsave(&local->sta_lock, flags);
ieee80211_beacon_add_tim(ap, skb, beacon);
spin_unlock_irqrestore(&local->sta_lock, flags);
}
if (beacon->tail)
memcpy(skb_put(skb, beacon->tail_len),
beacon->tail, beacon->tail_len);
} else
goto out;
} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_hdr *hdr;
if (!ifibss->probe_resp)
goto out;
skb = skb_copy(ifibss->probe_resp, GFP_ATOMIC);
if (!skb)
goto out;
hdr = (struct ieee80211_hdr *) skb->data;
hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_BEACON);
} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
struct ieee80211_mgmt *mgmt;
u8 *pos;
/* 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));
mgmt->frame_control =
cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
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 =
cpu_to_le16(local->hw.conf.beacon_int);
mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
pos = skb_put(skb, 2);
*pos++ = WLAN_EID_SSID;
*pos++ = 0x0;
mesh_mgmt_ies_add(skb, sdata);
} else {
WARN_ON(1);
goto out;
}
info = IEEE80211_SKB_CB(skb);
skb->do_not_encrypt = 1;
info->band = band;
/*
* 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);
info->control.vif = vif;
info->flags |= IEEE80211_TX_CTL_NO_ACK;
info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
out:
rcu_read_unlock();
return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);
void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
const void *frame, size_t frame_len,
const struct ieee80211_tx_info *frame_txctl,
struct ieee80211_rts *rts)
{
const struct ieee80211_hdr *hdr = frame;
rts->frame_control =
cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
frame_txctl);
memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);
void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
const void *frame, size_t frame_len,
const struct ieee80211_tx_info *frame_txctl,
struct ieee80211_cts *cts)
{
const struct ieee80211_hdr *hdr = frame;
cts->frame_control =
cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
cts->duration = ieee80211_ctstoself_duration(hw, vif,
frame_len, frame_txctl);
memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);
struct sk_buff *
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
struct ieee80211_vif *vif)
{
struct ieee80211_local *local = hw_to_local(hw);
struct sk_buff *skb = NULL;
struct sta_info *sta;
struct ieee80211_tx_data tx;
struct ieee80211_sub_if_data *sdata;
struct ieee80211_if_ap *bss = NULL;
struct beacon_data *beacon;
struct ieee80211_tx_info *info;
sdata = vif_to_sdata(vif);
bss = &sdata->u.ap;
if (!bss)
return NULL;
rcu_read_lock();
beacon = rcu_dereference(bss->beacon);
if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
goto out;
if (bss->dtim_count != 0)
goto out; /* send buffered bc/mc only after DTIM beacon */
while (1) {
skb = skb_dequeue(&bss->ps_bc_buf);
if (!skb)
goto out;
local->total_ps_buffered--;
if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
struct ieee80211_hdr *hdr =
(struct ieee80211_hdr *) skb->data;
/* more buffered multicast/broadcast frames ==> set
* MoreData flag in IEEE 802.11 header to inform PS
* STAs */
hdr->frame_control |=
cpu_to_le16(IEEE80211_FCTL_MOREDATA);
}
if (!ieee80211_tx_prepare(local, &tx, skb))
break;
dev_kfree_skb_any(skb);
}
info = IEEE80211_SKB_CB(skb);
sta = tx.sta;
tx.flags |= IEEE80211_TX_PS_BUFFERED;
tx.channel = local->hw.conf.channel;
info->band = tx.channel->band;
if (invoke_tx_handlers(&tx))
skb = NULL;
out:
rcu_read_unlock();
return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);
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