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linux/net/mac80211/tx.c
Johannes Berg f591fa5dbb mac80211: fix TX sequence numbers 
This patch makes mac80211 assign proper sequence numbers to
QoS-data frames. It also removes the old sequence number code
because we noticed that only the driver or hardware can assign
sequence numbers to non-QoS-data and especially management
frames in a race-free manner because beacons aren't passed
through mac80211's TX path.

This patch also adds temporary code to the rt2x00 drivers to
not break them completely, that code will have to be reworked
for proper sequence numbers on beacons.

It also moves sequence number assignment down in the TX path
so no sequence numbers are assigned to frames that are dropped.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-07-14 14:52:57 -04:00

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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_FRAG_AGAIN 2
/* misc utils */
#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
static void ieee80211_dump_frame(const char *ifname, const char *title,
const struct sk_buff *skb)
{
const struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
unsigned int hdrlen;
DECLARE_MAC_BUF(mac);
printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
if (skb->len < 4) {
printk("\n");
return;
}
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (hdrlen > skb->len)
hdrlen = skb->len;
if (hdrlen >= 4)
printk(" FC=0x%04x DUR=0x%04x",
le16_to_cpu(hdr->frame_control), le16_to_cpu(hdr->duration_id));
if (hdrlen >= 10)
printk(" A1=%s", print_mac(mac, hdr->addr1));
if (hdrlen >= 16)
printk(" A2=%s", print_mac(mac, hdr->addr2));
if (hdrlen >= 24)
printk(" A3=%s", print_mac(mac, hdr->addr3));
if (hdrlen >= 30)
printk(" A4=%s", print_mac(mac, hdr->addr4));
printk("\n");
}
#else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
static inline void ieee80211_dump_frame(const char *ifname, const char *title,
struct sk_buff *skb)
{
}
#endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
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;
sband = local->hw.wiphy->bands[tx->channel->band];
txrate = &sband->bitrates[tx->rate_idx];
erp = 0;
if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
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
*/
if ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) {
/* TODO: These control frames are not currently sent by
* 80211.o, 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->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->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->bss_conf.use_short_preamble);
}
return cpu_to_le16(dur);
}
static int inline is_ieee80211_device(struct net_device *dev,
struct net_device *master)
{
return (wdev_priv(dev->ieee80211_ptr) ==
wdev_priv(master->ieee80211_ptr));
}
/* tx handlers */
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
{
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
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->sta_sw_scanning) &&
((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
(tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
return TX_DROP;
if (tx->sdata->vif.type == IEEE80211_IF_TYPE_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 != IEEE80211_IF_TYPE_IBSS &&
(tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
DECLARE_MAC_BUF(mac);
printk(KERN_DEBUG "%s: dropped data frame to not "
"associated station %s\n",
tx->dev->name, print_mac(mac, hdr->addr1));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
return TX_DROP;
}
} else {
if (unlikely((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
tx->local->num_sta == 0 &&
tx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS)) {
/*
* 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 != IEEE80211_IF_TYPE_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 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);
/*
* 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 (tx->fc & IEEE80211_FCTL_ORDER)
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 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 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);
u32 staflags;
DECLARE_MAC_BUF(mac);
if (unlikely(!sta ||
((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
(tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
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 %s aid %d: PS buffer (entries "
"before %d)\n",
print_mac(mac, sta->addr), 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 MAC80211_VERBOSE_PS_DEBUG
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: STA %s TX "
"buffer full - dropping oldest frame\n",
tx->dev->name, print_mac(mac, 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 %s in PS mode, but pspoll "
"set -> send frame\n", tx->dev->name,
print_mac(mac, 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);
u16 fc = tx->fc;
if (unlikely(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT))
tx->key = NULL;
else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
tx->key = key;
else if ((key = rcu_dereference(tx->sdata->default_key)))
tx->key = key;
else if (tx->sdata->drop_unencrypted &&
!(info->flags & IEEE80211_TX_CTL_EAPOL_FRAME) &&
!(info->flags & IEEE80211_TX_CTL_INJECTED)) {
I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
return TX_DROP;
} else
tx->key = NULL;
if (tx->key) {
u16 ftype, stype;
tx->key->tx_rx_count++;
/* TODO: add threshold stuff again */
switch (tx->key->conf.alg) {
case ALG_WEP:
ftype = fc & IEEE80211_FCTL_FTYPE;
stype = fc & IEEE80211_FCTL_STYPE;
if (ftype == IEEE80211_FTYPE_MGMT &&
stype == IEEE80211_STYPE_AUTH)
break;
case ALG_TKIP:
case ALG_CCMP:
if (!WLAN_FC_DATA_PRESENT(fc))
tx->key = NULL;
break;
}
}
if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
{
struct rate_selection rsel;
struct ieee80211_supported_band *sband;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
sband = tx->local->hw.wiphy->bands[tx->channel->band];
if (likely(tx->rate_idx < 0)) {
rate_control_get_rate(tx->dev, sband, tx->skb, &rsel);
tx->rate_idx = rsel.rate_idx;
if (unlikely(rsel.probe_idx >= 0)) {
info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
tx->flags |= IEEE80211_TX_PROBE_LAST_FRAG;
info->control.alt_retry_rate_idx = tx->rate_idx;
tx->rate_idx = rsel.probe_idx;
} else
info->control.alt_retry_rate_idx = -1;
if (unlikely(tx->rate_idx < 0))
return TX_DROP;
} else
info->control.alt_retry_rate_idx = -1;
if (tx->sdata->bss_conf.use_cts_prot &&
(tx->flags & IEEE80211_TX_FRAGMENTED) && (rsel.nonerp_idx >= 0)) {
tx->last_frag_rate_idx = tx->rate_idx;
if (rsel.probe_idx >= 0)
tx->flags &= ~IEEE80211_TX_PROBE_LAST_FRAG;
else
tx->flags |= IEEE80211_TX_PROBE_LAST_FRAG;
tx->rate_idx = rsel.nonerp_idx;
info->tx_rate_idx = rsel.nonerp_idx;
info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
} else {
tx->last_frag_rate_idx = tx->rate_idx;
info->tx_rate_idx = tx->rate_idx;
}
info->tx_rate_idx = tx->rate_idx;
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_misc(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);
struct ieee80211_supported_band *sband;
sband = tx->local->hw.wiphy->bands[tx->channel->band];
if (tx->sta)
info->control.aid = tx->sta->aid;
if (!info->control.retry_limit) {
if (!is_multicast_ether_addr(hdr->addr1)) {
int len = min_t(int, tx->skb->len + FCS_LEN,
tx->local->fragmentation_threshold);
if (len > tx->local->rts_threshold
&& tx->local->rts_threshold <
IEEE80211_MAX_RTS_THRESHOLD) {
info->flags |= IEEE80211_TX_CTL_USE_RTS_CTS;
info->flags |=
IEEE80211_TX_CTL_LONG_RETRY_LIMIT;
info->control.retry_limit =
tx->local->long_retry_limit;
} else {
info->control.retry_limit =
tx->local->short_retry_limit;
}
} else {
info->control.retry_limit = 1;
}
}
if (tx->flags & IEEE80211_TX_FRAGMENTED) {
/* Do not use multiple retry rates when sending fragmented
* frames.
* TODO: The last fragment could still use multiple retry
* rates. */
info->control.alt_retry_rate_idx = -1;
}
/* Use CTS protection for unicast frames sent using extended rates if
* there are associated non-ERP stations and RTS/CTS is not configured
* for the frame. */
if ((tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE) &&
(sband->bitrates[tx->rate_idx].flags & IEEE80211_RATE_ERP_G) &&
(tx->flags & IEEE80211_TX_UNICAST) &&
tx->sdata->bss_conf.use_cts_prot &&
!(info->flags & IEEE80211_TX_CTL_USE_RTS_CTS))
info->flags |= IEEE80211_TX_CTL_USE_CTS_PROTECT;
/* Transmit data frames using short preambles if the driver supports
* short preambles at the selected rate and short preambles are
* available on the network at the current point in time. */
if (ieee80211_is_data(hdr->frame_control) &&
(sband->bitrates[tx->rate_idx].flags & IEEE80211_RATE_SHORT_PREAMBLE) &&
tx->sdata->bss_conf.use_short_preamble &&
(!tx->sta || test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))) {
info->flags |= IEEE80211_TX_CTL_SHORT_PREAMBLE;
}
if ((info->flags & IEEE80211_TX_CTL_USE_RTS_CTS) ||
(info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT)) {
struct ieee80211_rate *rate;
s8 baserate = -1;
int idx;
/* Do not use multiple retry rates when using RTS/CTS */
info->control.alt_retry_rate_idx = -1;
/* Use min(data rate, max base rate) as CTS/RTS rate */
rate = &sband->bitrates[tx->rate_idx];
for (idx = 0; idx < sband->n_bitrates; idx++) {
if (sband->bitrates[idx].bitrate > rate->bitrate)
continue;
if (tx->sdata->basic_rates & BIT(idx) &&
(baserate < 0 ||
(sband->bitrates[baserate].bitrate
< sband->bitrates[idx].bitrate)))
baserate = idx;
}
if (baserate >= 0)
info->control.rts_cts_rate_idx = baserate;
else
info->control.rts_cts_rate_idx = 0;
}
if (tx->sta)
info->control.aid = tx->sta->aid;
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;
/* only for injected frames */
if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
return TX_CONTINUE;
if (ieee80211_hdrlen(hdr->frame_control) < 24)
return TX_CONTINUE;
if (!ieee80211_is_data_qos(hdr->frame_control)) {
info->flags |= IEEE80211_TX_CTL_ASSIGN_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 ieee80211_tx_result debug_noinline
ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
size_t hdrlen, per_fragm, num_fragm, payload_len, left;
struct sk_buff **frags, *first, *frag;
int i;
u16 seq;
u8 *pos;
int frag_threshold = tx->local->fragmentation_threshold;
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(tx->flags & IEEE80211_TX_CTL_AMPDU ||
skb_get_queue_mapping(tx->skb) >=
ieee80211_num_regular_queues(&tx->local->hw)))
return TX_DROP;
first = tx->skb;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
payload_len = first->len - hdrlen;
per_fragm = frag_threshold - hdrlen - FCS_LEN;
num_fragm = DIV_ROUND_UP(payload_len, per_fragm);
frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
if (!frags)
goto fail;
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
pos = first->data + hdrlen + per_fragm;
left = payload_len - per_fragm;
for (i = 0; i < num_fragm - 1; i++) {
struct ieee80211_hdr *fhdr;
size_t copylen;
if (left <= 0)
goto fail;
/* reserve enough extra head and tail room for possible
* encryption */
frag = frags[i] =
dev_alloc_skb(tx->local->tx_headroom +
frag_threshold +
IEEE80211_ENCRYPT_HEADROOM +
IEEE80211_ENCRYPT_TAILROOM);
if (!frag)
goto fail;
/* Make sure that all fragments use the same priority so
* that they end up using the same TX queue */
frag->priority = first->priority;
skb_reserve(frag, tx->local->tx_headroom +
IEEE80211_ENCRYPT_HEADROOM);
fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
memcpy(fhdr, first->data, hdrlen);
if (i == num_fragm - 2)
fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
copylen = left > per_fragm ? per_fragm : left;
memcpy(skb_put(frag, copylen), pos, copylen);
memcpy(frag->cb, first->cb, sizeof(frag->cb));
skb_copy_queue_mapping(frag, first);
pos += copylen;
left -= copylen;
}
skb_trim(first, hdrlen + per_fragm);
tx->num_extra_frag = num_fragm - 1;
tx->extra_frag = frags;
return TX_CONTINUE;
fail:
if (frags) {
for (i = 0; i < num_fragm - 1; i++)
if (frags[i])
dev_kfree_skb(frags[i]);
kfree(frags);
}
I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
return TX_DROP;
}
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);
}
/* 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 ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
int next_len, i;
int group_addr = is_multicast_ether_addr(hdr->addr1);
if (!(tx->flags & IEEE80211_TX_FRAGMENTED)) {
hdr->duration_id = ieee80211_duration(tx, group_addr, 0);
return TX_CONTINUE;
}
hdr->duration_id = ieee80211_duration(tx, group_addr,
tx->extra_frag[0]->len);
for (i = 0; i < tx->num_extra_frag; i++) {
if (i + 1 < tx->num_extra_frag) {
next_len = tx->extra_frag[i + 1]->len;
} else {
next_len = 0;
tx->rate_idx = tx->last_frag_rate_idx;
}
hdr = (struct ieee80211_hdr *)tx->extra_frag[i]->data;
hdr->duration_id = ieee80211_duration(tx, 0, next_len);
}
return TX_CONTINUE;
}
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
{
int i;
if (!tx->sta)
return TX_CONTINUE;
tx->sta->tx_packets++;
tx->sta->tx_fragments++;
tx->sta->tx_bytes += tx->skb->len;
if (tx->extra_frag) {
tx->sta->tx_fragments += tx->num_extra_frag;
for (i = 0; i < tx->num_extra_frag; i++)
tx->sta->tx_bytes += tx->extra_frag[i]->len;
}
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);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
sband = tx->local->hw.wiphy->bands[tx->channel->band];
info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
info->flags |= IEEE80211_TX_CTL_INJECTED;
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) {
int i, target_rate;
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_RATE:
/*
* radiotap rate u8 is in 500kbps units eg, 0x02=1Mbps
* ieee80211 rate int is in 100kbps units eg, 0x0a=1Mbps
*/
target_rate = (*iterator.this_arg) * 5;
for (i = 0; i < sband->n_bitrates; i++) {
struct ieee80211_rate *r;
r = &sband->bitrates[i];
if (r->bitrate == target_rate) {
tx->rate_idx = i;
break;
}
}
break;
case IEEE80211_RADIOTAP_ANTENNA:
/*
* radiotap uses 0 for 1st ant, mac80211 is 1 for
* 1st ant
*/
info->antenna_sel_tx = (*iterator.this_arg) + 1;
break;
#if 0
case IEEE80211_RADIOTAP_DBM_TX_POWER:
control->power_level = *iterator.this_arg;
break;
#endif
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)
info->flags &=
~IEEE80211_TX_CTL_DO_NOT_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 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;
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;
tx->rate_idx = -1;
tx->last_frag_rate_idx = -1;
/*
* 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(sdata->vif.type == IEEE80211_IF_TYPE_MNTR)) {
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.
*/
}
hdr = (struct ieee80211_hdr *) skb->data;
tx->sta = sta_info_get(local, hdr->addr1);
tx->fc = le16_to_cpu(hdr->frame_control);
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 &&
!local->ops->set_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_get_hdrlen(tx->fc);
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_tx_data *tx,
struct sk_buff *skb,
struct net_device *mdev)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct net_device *dev;
dev = dev_get_by_index(&init_net, info->control.ifindex);
if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
dev_put(dev);
dev = NULL;
}
if (unlikely(!dev))
return -ENODEV;
/* initialises tx with control */
__ieee80211_tx_prepare(tx, skb, dev);
dev_put(dev);
return 0;
}
static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
struct ieee80211_tx_data *tx)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int ret, i;
if (netif_subqueue_stopped(local->mdev, skb))
return IEEE80211_TX_AGAIN;
if (skb) {
ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
"TX to low-level driver", skb);
ret = local->ops->tx(local_to_hw(local), skb);
if (ret)
return IEEE80211_TX_AGAIN;
local->mdev->trans_start = jiffies;
ieee80211_led_tx(local, 1);
}
if (tx->extra_frag) {
for (i = 0; i < tx->num_extra_frag; i++) {
if (!tx->extra_frag[i])
continue;
info = IEEE80211_SKB_CB(tx->extra_frag[i]);
info->flags &= ~(IEEE80211_TX_CTL_USE_RTS_CTS |
IEEE80211_TX_CTL_USE_CTS_PROTECT |
IEEE80211_TX_CTL_CLEAR_PS_FILT |
IEEE80211_TX_CTL_FIRST_FRAGMENT);
if (netif_subqueue_stopped(local->mdev,
tx->extra_frag[i]))
return IEEE80211_TX_FRAG_AGAIN;
if (i == tx->num_extra_frag) {
info->tx_rate_idx = tx->last_frag_rate_idx;
if (tx->flags & IEEE80211_TX_PROBE_LAST_FRAG)
info->flags |=
IEEE80211_TX_CTL_RATE_CTRL_PROBE;
else
info->flags &=
~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
}
ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
"TX to low-level driver",
tx->extra_frag[i]);
ret = local->ops->tx(local_to_hw(local),
tx->extra_frag[i]);
if (ret)
return IEEE80211_TX_FRAG_AGAIN;
local->mdev->trans_start = jiffies;
ieee80211_led_tx(local, 1);
tx->extra_frag[i] = NULL;
}
kfree(tx->extra_frag);
tx->extra_frag = NULL;
}
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;
int i;
#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);
dev_kfree_skb(skb);
for (i = 0; i < tx->num_extra_frag; i++)
if (tx->extra_frag[i])
dev_kfree_skb(tx->extra_frag[i]);
kfree(tx->extra_frag);
return -1;
} else if (unlikely(res == TX_QUEUED)) {
I802_DEBUG_INC(tx->local->tx_handlers_queued);
return -1;
}
return 0;
}
static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb)
{
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);
int ret, i;
u16 queue;
queue = skb_get_queue_mapping(skb);
WARN_ON(test_bit(queue, local->queues_pending));
if (unlikely(skb->len < 10)) {
dev_kfree_skb(skb);
return 0;
}
rcu_read_lock();
/* initialises tx */
res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
if (res_prepare == TX_DROP) {
dev_kfree_skb(skb);
rcu_read_unlock();
return 0;
}
sta = tx.sta;
tx.channel = local->hw.conf.channel;
info->band = tx.channel->band;
if (invoke_tx_handlers(&tx))
goto out;
retry:
ret = __ieee80211_tx(local, skb, &tx);
if (ret) {
struct ieee80211_tx_stored_packet *store;
/*
* 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(queue >= ieee80211_num_regular_queues(&local->hw)))
goto drop;
store = &local->pending_packet[queue];
if (ret == IEEE80211_TX_FRAG_AGAIN)
skb = NULL;
set_bit(queue, local->queues_pending);
smp_mb();
/*
* When the driver gets out of buffers during sending of
* fragments and calls ieee80211_stop_queue, the netif
* subqueue is stopped. There is, however, a small window
* in which the PENDING bit is not yet set. If a buffer
* gets available in that window (i.e. driver calls
* ieee80211_wake_queue), we would end up with ieee80211_tx
* called with the PENDING bit still set. Prevent this by
* continuing transmitting here when that situation is
* possible to have happened.
*/
if (!__netif_subqueue_stopped(local->mdev, queue)) {
clear_bit(queue, local->queues_pending);
goto retry;
}
store->skb = skb;
store->extra_frag = tx.extra_frag;
store->num_extra_frag = tx.num_extra_frag;
store->last_frag_rate_idx = tx.last_frag_rate_idx;
store->last_frag_rate_ctrl_probe =
!!(tx.flags & IEEE80211_TX_PROBE_LAST_FRAG);
}
out:
rcu_read_unlock();
return 0;
drop:
if (skb)
dev_kfree_skb(skb);
for (i = 0; i < tx.num_extra_frag; i++)
if (tx.extra_frag[i])
dev_kfree_skb(tx.extra_frag[i]);
kfree(tx.extra_frag);
rcu_read_unlock();
return 0;
}
/* 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_tx_info *info = IEEE80211_SKB_CB(skb);
struct net_device *odev = NULL;
struct ieee80211_sub_if_data *osdata;
int headroom;
bool may_encrypt;
int ret;
if (info->control.ifindex)
odev = dev_get_by_index(&init_net, info->control.ifindex);
if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
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 0;
}
osdata = IEEE80211_DEV_TO_SUB_IF(odev);
may_encrypt = !(info->flags & IEEE80211_TX_CTL_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 0;
}
info->control.vif = &osdata->vif;
ret = ieee80211_tx(odev, skb);
dev_put(odev);
return ret;
}
int ieee80211_monitor_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_radiotap_header *prthdr =
(struct ieee80211_radiotap_header *)skb->data;
u16 len_rthdr;
/* 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 */
info->control.ifindex = dev->ifindex;
info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
/* Interfaces should always request a status report */
info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
/*
* 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_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_tx_info *info;
struct ieee80211_sub_if_data *sdata;
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;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
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 IEEE80211_IF_TYPE_AP:
case IEEE80211_IF_TYPE_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 IEEE80211_IF_TYPE_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 IEEE80211_IF_TYPE_MESH_POINT:
fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
/* RA TA DA SA */
if (is_multicast_ether_addr(skb->data))
memcpy(hdr.addr1, skb->data, ETH_ALEN);
else if (mesh_nexthop_lookup(hdr.addr1, skb, dev))
return 0;
memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
memcpy(hdr.addr3, skb->data, ETH_ALEN);
memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
if (skb->pkt_type == PACKET_OTHERHOST) {
/* Forwarded frame, keep mesh ttl and seqnum */
struct ieee80211s_hdr *prev_meshhdr;
prev_meshhdr = ((struct ieee80211s_hdr *)skb->cb);
meshhdrlen = ieee80211_get_mesh_hdrlen(prev_meshhdr);
memcpy(&mesh_hdr, prev_meshhdr, meshhdrlen);
sdata->u.sta.mshstats.fwded_frames++;
} else {
if (!sdata->u.sta.mshcfg.dot11MeshTTL) {
/* Do not send frames with mesh_ttl == 0 */
sdata->u.sta.mshstats.dropped_frames_ttl++;
ret = 0;
goto fail;
}
meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
sdata);
}
hdrlen = 30;
break;
#endif
case IEEE80211_IF_TYPE_STA:
fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
/* BSSID SA DA */
memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
memcpy(hdr.addr3, skb->data, ETH_ALEN);
hdrlen = 24;
break;
case IEEE80211_IF_TYPE_IBSS:
/* DA SA BSSID */
memcpy(hdr.addr1, skb->data, ETH_ALEN);
memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
memcpy(hdr.addr3, sdata->u.sta.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 &&
ieee80211_num_regular_queues(&local->hw) >= 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 (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
DECLARE_MAC_BUF(mac);
if (net_ratelimit())
printk(KERN_DEBUG "%s: dropped frame to %s"
" (unauthorized port)\n", dev->name,
print_mac(mac, 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;
/* TODO: implement support for fragments so that there is no need to
* reallocate and copy payload; it might be enough to support one
* extra fragment that would be copied in the beginning of the frame
* data.. anyway, it would be nice to include this into skb structure
* somehow
*
* There are few options for this:
* use skb->cb as an extra space for 802.11 header
* allocate new buffer if not enough headroom
* make sure that there is enough headroom in every skb by increasing
* build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
* alloc_skb() (net/core/skbuff.c)
*/
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;
info = IEEE80211_SKB_CB(skb);
memset(info, 0, sizeof(*info));
info->control.ifindex = dev->ifindex;
if (ethertype == ETH_P_PAE)
info->flags |= IEEE80211_TX_CTL_EAPOL_FRAME;
/* Interfaces should always request a status report */
info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
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, j;
struct ieee80211_tx_stored_packet *store;
for (i = 0; i < ieee80211_num_regular_queues(&local->hw); i++) {
if (!test_bit(i, local->queues_pending))
continue;
store = &local->pending_packet[i];
kfree_skb(store->skb);
for (j = 0; j < store->num_extra_frag; j++)
kfree_skb(store->extra_frag[j]);
kfree(store->extra_frag);
clear_bit(i, local->queues_pending);
}
}
/*
* 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;
struct ieee80211_tx_stored_packet *store;
struct ieee80211_tx_data tx;
int i, ret;
netif_tx_lock_bh(dev);
for (i = 0; i < ieee80211_num_regular_queues(&local->hw); i++) {
/* Check that this queue is ok */
if (__netif_subqueue_stopped(local->mdev, i))
continue;
if (!test_bit(i, local->queues_pending)) {
ieee80211_wake_queue(&local->hw, i);
continue;
}
store = &local->pending_packet[i];
tx.extra_frag = store->extra_frag;
tx.num_extra_frag = store->num_extra_frag;
tx.last_frag_rate_idx = store->last_frag_rate_idx;
tx.flags = 0;
if (store->last_frag_rate_ctrl_probe)
tx.flags |= IEEE80211_TX_PROBE_LAST_FRAG;
ret = __ieee80211_tx(local, store->skb, &tx);
if (ret) {
if (ret == IEEE80211_TX_FRAG_AGAIN)
store->skb = NULL;
} else {
clear_bit(i, local->queues_pending);
ieee80211_wake_queue(&local->hw, i);
}
}
netif_tx_unlock_bh(dev);
}
/* functions for drivers to get certain frames */
static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
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 net_device *bdev;
struct ieee80211_sub_if_data *sdata = NULL;
struct ieee80211_if_ap *ap = NULL;
struct ieee80211_if_sta *ifsta = NULL;
struct rate_selection rsel;
struct beacon_data *beacon;
struct ieee80211_supported_band *sband;
struct ieee80211_mgmt *mgmt;
int *num_beacons;
enum ieee80211_band band = local->hw.conf.channel->band;
u8 *pos;
sband = local->hw.wiphy->bands[band];
rcu_read_lock();
sdata = vif_to_sdata(vif);
bdev = sdata->dev;
if (sdata->vif.type == IEEE80211_IF_TYPE_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(local, ap, skb, beacon);
} else {
unsigned long flags;
spin_lock_irqsave(&local->sta_lock, flags);
ieee80211_beacon_add_tim(local, 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);
num_beacons = &ap->num_beacons;
} else
goto out;
} else if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
struct ieee80211_hdr *hdr;
ifsta = &sdata->u.sta;
if (!ifsta->probe_resp)
goto out;
skb = skb_copy(ifsta->probe_resp, GFP_ATOMIC);
if (!skb)
goto out;
hdr = (struct ieee80211_hdr *) skb->data;
hdr->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
IEEE80211_STYPE_BEACON);
num_beacons = &ifsta->num_beacons;
} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
/* 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->dev);
num_beacons = &sdata->u.sta.num_beacons;
} else {
WARN_ON(1);
goto out;
}
info = IEEE80211_SKB_CB(skb);
info->band = band;
rate_control_get_rate(local->mdev, sband, skb, &rsel);
if (unlikely(rsel.rate_idx < 0)) {
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: ieee80211_beacon_get: "
"no rate found\n",
wiphy_name(local->hw.wiphy));
}
dev_kfree_skb(skb);
skb = NULL;
goto out;
}
info->control.vif = vif;
info->tx_rate_idx = rsel.rate_idx;
info->flags |= IEEE80211_TX_CTL_NO_ACK;
info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
if (sdata->bss_conf.use_short_preamble &&
sband->bitrates[rsel.rate_idx].flags & IEEE80211_RATE_SHORT_PREAMBLE)
info->flags |= IEEE80211_TX_CTL_SHORT_PREAMBLE;
info->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
info->control.retry_limit = 1;
(*num_beacons)++;
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 net_device *bdev;
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);
bdev = sdata->dev;
bss = &sdata->u.ap;
if (!bss)
return NULL;
rcu_read_lock();
beacon = rcu_dereference(bss->beacon);
if (sdata->vif.type != IEEE80211_IF_TYPE_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(&tx, skb, local->mdev))
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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