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tx.c
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/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <[email protected]>
* Copyright 2007 Johannes Berg <[email protected]>
*
* 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;
info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
/* device releases frame after DTIM beacon */
if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
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_STA | WLAN_STA_PS_DRIVER)) &&
!(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 wakes up/polls,
* but don't set the TIM bit if the driver is blocking
* wakeup or poll response transmissions anyway.
*/
if (skb_queue_empty(&sta->ps_tx_buf) &&
!(staflags & WLAN_STA_PS_DRIVER))
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(staflags & WLAN_STA_PS_STA)) {
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