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linux/net/mac80211/tx.c
Igor Perminov 1f08e84ff6 mac80211: Fix [re]association power saving issue on AP side 
Consider the following step-by step:
1. A STA authenticates and associates with the AP and exchanges
traffic.
2. The STA reports to the AP that it is going to PS state.
3. Some time later the STA device goes to the stand-by mode (not only
its wi-fi card, but the device itself) and drops the association state
without sending a disassociation frame.
4. The STA device wakes up and begins authentication with an
Auth frame as it hasn't been authenticated/associated previously.

At the step 4 the AP "remembers" the STA and considers it is still in
the PS state, so the AP buffers frames, which it has to send to the STA.
But the STA isn't actually in the PS state and so it neither checks
TIM bits nor reports to the AP that it isn't power saving.
Because of that authentication/[re]association fails.

To fix authentication/[re]association stage of this issue, Auth, Assoc
Resp and Reassoc Resp frames are transmitted disregarding of STA's power
saving state.

N.B. This patch doesn't fix further data frame exchange after
authentication/[re]association. A patch in hostapd is required to fix
that.

Signed-off-by: Igor Perminov <igor.perminov@inbox.ru>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-29 17:25:15 -04:00

2236 lines
61 KiB
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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 "driver-ops.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(test_bit(SCAN_OFF_CHANNEL, &tx->local->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 hardware */
if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING)) {
info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
return TX_CONTINUE;
}
/* buffered in mac80211 */
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;
}
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)
|| ieee80211_is_auth(hdr->frame_control)
|| ieee80211_is_assoc_resp(hdr->frame_control)
|| ieee80211_is_reassoc_resp(hdr->frame_control)))
return TX_CONTINUE;
staflags = get_sta_flags(sta);
if (unlikely((staflags & WLAN_STA_PS) &&
!(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
#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;
info->control.vif = &tx->sdata->vif;
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
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 */
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 = NULL;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_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))
info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
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;
u32 sta_flags;
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->hw.wiphy->frag_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 (len > tx->local->hw.wiphy->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;
sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
/*
* Lets not bother rate control if we're associated and cannot
* talk to the sta. This should not happen.
*/
if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) &&
(sta_flags & WLAN_STA_ASSOC) &&
!rate_usable_index_exists(sband, &tx->sta->sta),
"%s: Dropped data frame as no usable bitrate found while "
"scanning and associated. Target station: "
"%pM on %d GHz band\n",
tx->dev->name, hdr->addr1,
tx->channel->band ? 5 : 2))
return TX_DROP;
/*
* If we're associated with the sta at this point we know we can at
* least send the frame at the lowest bit rate.
*/
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 (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
(info->flags & IEEE80211_TX_CTL_NO_ACK)))
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->type == NL80211_IFTYPE_MONITOR))
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;
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->dev = skb->dev;
/* 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->hw.wiphy->frag_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 + FCS_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_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;
}
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;
if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
break; /* must not overwrite AID */
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;
}
/* actual transmit path */
/*
* deal with packet injection down monitor interface
* with Radiotap Header -- only called for monitor mode interface
*/
static bool __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;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
sband = tx->local->hw.wiphy->bands[tx->channel->band];
info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
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 false;
skb_trim(skb, skb->len - FCS_LEN);
}
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
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 false;
/*
* remove the radiotap header
* iterator->max_length was sanity-checked against
* skb->len by iterator init
*/
skb_pull(skb, iterator.max_length);
return true;
}
/*
* initialises @tx
*/
static ieee80211_tx_result
ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
struct ieee80211_tx_data *tx,
struct sk_buff *skb)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_hdr *hdr;
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 = sdata->dev; /* use original interface */
tx->local = local;
tx->sdata = sdata;
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 */
if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
if (!__ieee80211_parse_tx_radiotap(tx, skb))
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->control.vif = &sdata->vif;
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;
if (unlikely(local->wifi_wme_noack_test))
info->flags |= IEEE80211_TX_CTL_NO_ACK;
else
info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
}
if (tx->flags & IEEE80211_TX_FRAGMENTED) {
if ((tx->flags & IEEE80211_TX_UNICAST) &&
skb->len + FCS_LEN > local->hw.wiphy->frag_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;
}
static int __ieee80211_tx(struct ieee80211_local *local,
struct sk_buff **skbp,
struct sta_info *sta,
bool txpending)
{
struct sk_buff *skb = *skbp, *next;
struct ieee80211_tx_info *info;
struct ieee80211_sub_if_data *sdata;
unsigned long flags;
int ret, len;
bool fragm = false;
while (skb) {
int q = skb_get_queue_mapping(skb);
spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
ret = IEEE80211_TX_OK;
if (local->queue_stop_reasons[q] ||
(!txpending && !skb_queue_empty(&local->pending[q])))
ret = IEEE80211_TX_PENDING;
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
if (ret != IEEE80211_TX_OK)
return ret;
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;
if (next)
info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
sdata = vif_to_sdata(info->control.vif);
switch (sdata->vif.type) {
case NL80211_IFTYPE_MONITOR:
info->control.vif = NULL;
break;
case NL80211_IFTYPE_AP_VLAN:
info->control.vif = &container_of(sdata->bss,
struct ieee80211_sub_if_data, u.ap)->vif;
break;
default:
/* keep */
break;
}
ret = drv_tx(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) {
info->control.vif = &sdata->vif;
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_stats)
CALL_TXH(ieee80211_tx_h_encrypt)
CALL_TXH(ieee80211_tx_h_calculate_duration)
#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 ieee80211_sub_if_data *sdata,
struct sk_buff *skb, bool txpending)
{
struct ieee80211_local *local = sdata->local;
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);
if (unlikely(skb->len < 10)) {
dev_kfree_skb(skb);
return;
}
rcu_read_lock();
/* initialises tx */
res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
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;
}
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, txpending);
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 (local->queue_stop_reasons[queue] ||
!skb_queue_empty(&local->pending[queue])) {
/*
* if queue is stopped, queue up frames for later
* transmission from the tasklet
*/
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));
spin_unlock_irqrestore(&local->queue_stop_reason_lock,
flags);
} else {
/*
* otherwise retry, but this is a race condition or
* a driver bug (which we warn about if it persists)
*/
spin_unlock_irqrestore(&local->queue_stop_reason_lock,
flags);
retries++;
if (WARN(retries > 10, "tx refused but queue active\n"))
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;
}
static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_sub_if_data *tmp_sdata;
int headroom;
bool may_encrypt;
dev_hold(sdata->dev);
if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
local->hw.conf.dynamic_ps_timeout > 0 &&
!(local->scanning) && local->ps_sdata) {
if (local->hw.conf.flags & IEEE80211_CONF_PS) {
ieee80211_stop_queues_by_reason(&local->hw,
IEEE80211_QUEUE_STOP_REASON_PS);
ieee80211_queue_work(&local->hw,
&local->dynamic_ps_disable_work);
}
mod_timer(&local->dynamic_ps_timer, jiffies +
msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
}
info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
int hdrlen;
u16 len_rthdr;
info->flags |= IEEE80211_TX_CTL_INJECTED;
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(tmp_sdata, &local->interfaces,
list) {
if (!netif_running(tmp_sdata->dev))
continue;
if (tmp_sdata->vif.type != NL80211_IFTYPE_AP)
continue;
if (compare_ether_addr(tmp_sdata->dev->dev_addr,
hdr->addr2)) {
dev_hold(tmp_sdata->dev);
dev_put(sdata->dev);
sdata = tmp_sdata;
break;
}
}
rcu_read_unlock();
}
}
may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
headroom = local->tx_headroom;
if (may_encrypt)
headroom += IEEE80211_ENCRYPT_HEADROOM;
headroom -= skb_headroom(skb);
headroom = max_t(int, 0, headroom);
if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
dev_kfree_skb(skb);
dev_put(sdata->dev);
return;
}
info->control.vif = &sdata->vif;
if (ieee80211_vif_is_mesh(&sdata->vif) &&
ieee80211_is_data(hdr->frame_control) &&
!is_multicast_ether_addr(hdr->addr1))
if (mesh_nexthop_lookup(skb, sdata)) {
/* skb queued: don't free */
dev_put(sdata->dev);
return;
}
ieee80211_select_queue(local, skb);
ieee80211_tx(sdata, skb, false);
dev_put(sdata->dev);
}
netdev_tx_t 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;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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 */
/*
* 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);
memset(info, 0, sizeof(*info));
/* pass the radiotap header up to xmit */
ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), 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).
*/
netdev_tx_t 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;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int ret = NETDEV_TX_BUSY, 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 = NETDEV_TX_OK;
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:
if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
/* Do not send frames with mesh_ttl == 0 */
sdata->u.mesh.mshstats.dropped_frames_ttl++;
ret = NETDEV_TX_OK;
goto fail;
}
if (compare_ether_addr(dev->dev_addr,
skb->data + ETH_ALEN) == 0) {
hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
skb->data, skb->data + ETH_ALEN);
meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
sdata, NULL, NULL, NULL);
} else {
/* packet from other interface */
struct mesh_path *mppath;
int is_mesh_mcast = 1;
char *mesh_da;
rcu_read_lock();
if (is_multicast_ether_addr(skb->data))
/* DA TA mSA AE:SA */
mesh_da = skb->data;
else {
mppath = mpp_path_lookup(skb->data, sdata);
if (mppath) {
/* RA TA mDA mSA AE:DA SA */
mesh_da = mppath->mpp;
is_mesh_mcast = 0;
} else
/* DA TA mSA AE:SA */
mesh_da = dev->broadcast;
}
hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
mesh_da, dev->dev_addr);
rcu_read_unlock();
if (is_mesh_mcast)
meshhdrlen =
ieee80211_new_mesh_header(&mesh_hdr,
sdata,
skb->data + ETH_ALEN,
NULL,
NULL);
else
meshhdrlen =
ieee80211_new_mesh_header(&mesh_hdr,
sdata,
NULL,
skb->data,
skb->data + ETH_ALEN);
}
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 = NETDEV_TX_OK;
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 = NETDEV_TX_OK;
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;
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);
memset(info, 0, sizeof(*info));
dev->trans_start = jiffies;
ieee80211_xmit(sdata, skb);
return NETDEV_TX_OK;
fail:
if (ret == NETDEV_TX_OK)
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;
int ret;
bool result = true;
sdata = vif_to_sdata(info->control.vif);
if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
ieee80211_tx(sdata, skb, true);
} else {
hdr = (struct ieee80211_hdr *)skb->data;
sta = sta_info_get(local, hdr->addr1);
ret = __ieee80211_tx(local, &skb, sta, true);
if (ret != IEEE80211_TX_OK)
result = false;
}
return result;
}
/*
* Transmit all pending packets. Called from tasklet.
*/
void ieee80211_tx_pending(unsigned long data)
{
struct ieee80211_local *local = (struct ieee80211_local *)data;
unsigned long flags;
int i;
bool txok;
rcu_read_lock();
spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
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.
*/
if (local->queue_stop_reasons[i] ||
skb_queue_empty(&local->pending[i]))
continue;
while (!skb_queue_empty(&local->pending[i])) {
struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_sub_if_data *sdata;
if (WARN_ON(!info->control.vif)) {
kfree_skb(skb);
continue;
}
sdata = vif_to_sdata(info->control.vif);
dev_hold(sdata->dev);
spin_unlock_irqrestore(&local->queue_stop_reason_lock,
flags);
txok = ieee80211_tx_pending_skb(local, skb);
dev_put(sdata->dev);
if (!txok)
__skb_queue_head(&local->pending[i], skb);
spin_lock_irqsave(&local->queue_stop_reason_lock,
flags);
if (!txok)
break;
}
}
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
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;
struct sk_buff *presp = rcu_dereference(ifibss->presp);
if (!presp)
goto out;
skb = skb_copy(presp, 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(sdata->vif.bss_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);
info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
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;
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(sdata, &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);
void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
int encrypt)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
skb_set_mac_header(skb, 0);
skb_set_network_header(skb, 0);
skb_set_transport_header(skb, 0);
if (!encrypt)
info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
/*
* The other path calling ieee80211_xmit is from the tasklet,
* and while we can handle concurrent transmissions locking
* requirements are that we do not come into tx with bhs on.
*/
local_bh_disable();
ieee80211_xmit(sdata, skb);
local_bh_enable();
}
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