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linux/net/mac80211/tx.c
David S. Miller 608961a5ec mac80211: Use skb_header_cloned() on TX path. 
When skb_header_cloned() returns false you can change the
headers however you like.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-12 21:59:32 -07:00

2025 lines
56 KiB
C
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/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*
* Transmit and frame generation functions.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/bitmap.h>
#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/ieee80211_radiotap.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "led.h"
#include "mesh.h"
#include "wep.h"
#include "wpa.h"
#include "wme.h"
#include "rate.h"
#define IEEE80211_TX_OK 0
#define IEEE80211_TX_AGAIN 1
#define IEEE80211_TX_FRAG_AGAIN 2
/* misc utils */
static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
struct ieee80211_hdr *hdr)
{
/* Set the sequence number for this frame. */
hdr->seq_ctrl = cpu_to_le16(sdata->sequence);
/* Increase the sequence number. */
sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
}
#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;
u16 fc;
int hdrlen;
DECLARE_MAC_BUF(mac);
printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
if (skb->len < 4) {
printk("\n");
return;
}
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if (hdrlen > skb->len)
hdrlen = skb->len;
if (hdrlen >= 4)
printk(" FC=0x%04x DUR=0x%04x",
fc, 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 u16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
int next_frag_len)
{
int rate, mrate, erp, dur, i;
struct ieee80211_rate *txrate = tx->rate;
struct ieee80211_local *local = tx->local;
struct ieee80211_supported_band *sband;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
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 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 dur;
}
static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
int queue)
{
return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
}
static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
int queue)
{
return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
}
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
ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
{
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
struct sk_buff *skb = tx->skb;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
u32 sta_flags;
if (unlikely(tx->flags & IEEE80211_TX_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 ? tx->sta->flags : 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;
}
static ieee80211_tx_result
ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
if (ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)) >= 24)
ieee80211_include_sequence(tx->sdata, hdr);
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->dev == local->mdev ||
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;
printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
wiphy_name(local->hw.wiphy), purged);
}
static ieee80211_tx_result
ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
{
/*
* 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.
*/
/* not AP/IBSS or ordered frame */
if (!tx->sdata->bss || (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) {
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: BC TX buffer full - "
"dropping the oldest frame\n",
tx->dev->name);
}
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 */
tx->control->flags |= IEEE80211_TXCTL_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;
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;
if (unlikely((sta->flags & WLAN_STA_PS) &&
!(sta->flags & WLAN_STA_PSPOLL))) {
struct ieee80211_tx_packet_data *pkt_data;
#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);
if (net_ratelimit()) {
printk(KERN_DEBUG "%s: STA %s TX "
"buffer full - dropping oldest frame\n",
tx->dev->name, print_mac(mac, sta->addr));
}
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);
pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
pkt_data->jiffies = jiffies;
skb_queue_tail(&sta->ps_tx_buf, tx->skb);
return TX_QUEUED;
}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
else if (unlikely(sta->flags & 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 */
sta->flags &= ~WLAN_STA_PSPOLL;
return TX_CONTINUE;
}
static ieee80211_tx_result
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
ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
{
struct ieee80211_key *key;
u16 fc = tx->fc;
if (unlikely(tx->control->flags & IEEE80211_TXCTL_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 &&
!(tx->control->flags & IEEE80211_TXCTL_EAPOL_FRAME) &&
!(tx->flags & IEEE80211_TX_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))
tx->control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
return TX_CONTINUE;
}
static ieee80211_tx_result
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;
first = tx->skb;
hdrlen = ieee80211_get_hdrlen(tx->fc);
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);
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:
printk(KERN_DEBUG "%s: failed to fragment frame\n", tx->dev->name);
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
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
ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
{
struct rate_selection rsel;
struct ieee80211_supported_band *sband;
sband = tx->local->hw.wiphy->bands[tx->local->hw.conf.channel->band];
if (likely(!tx->rate)) {
rate_control_get_rate(tx->dev, sband, tx->skb, &rsel);
tx->rate = rsel.rate;
if (unlikely(rsel.probe)) {
tx->control->flags |=
IEEE80211_TXCTL_RATE_CTRL_PROBE;
tx->flags |= IEEE80211_TX_PROBE_LAST_FRAG;
tx->control->alt_retry_rate = tx->rate;
tx->rate = rsel.probe;
} else
tx->control->alt_retry_rate = NULL;
if (!tx->rate)
return TX_DROP;
} else
tx->control->alt_retry_rate = NULL;
if (tx->sdata->bss_conf.use_cts_prot &&
(tx->flags & IEEE80211_TX_FRAGMENTED) && rsel.nonerp) {
tx->last_frag_rate = tx->rate;
if (rsel.probe)
tx->flags &= ~IEEE80211_TX_PROBE_LAST_FRAG;
else
tx->flags |= IEEE80211_TX_PROBE_LAST_FRAG;
tx->rate = rsel.nonerp;
tx->control->tx_rate = rsel.nonerp;
tx->control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
} else {
tx->last_frag_rate = tx->rate;
tx->control->tx_rate = tx->rate;
}
tx->control->tx_rate = tx->rate;
return TX_CONTINUE;
}
static ieee80211_tx_result
ieee80211_tx_h_misc(struct ieee80211_tx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
u16 fc = le16_to_cpu(hdr->frame_control);
u16 dur;
struct ieee80211_tx_control *control = tx->control;
if (!control->retry_limit) {
if (!is_multicast_ether_addr(hdr->addr1)) {
if (tx->skb->len + FCS_LEN > tx->local->rts_threshold
&& tx->local->rts_threshold <
IEEE80211_MAX_RTS_THRESHOLD) {
control->flags |=
IEEE80211_TXCTL_USE_RTS_CTS;
control->flags |=
IEEE80211_TXCTL_LONG_RETRY_LIMIT;
control->retry_limit =
tx->local->long_retry_limit;
} else {
control->retry_limit =
tx->local->short_retry_limit;
}
} else {
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. */
control->alt_retry_rate = NULL;
}
/* 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) &&
(tx->rate->flags & IEEE80211_RATE_ERP_G) &&
(tx->flags & IEEE80211_TX_UNICAST) &&
tx->sdata->bss_conf.use_cts_prot &&
!(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
control->flags |= IEEE80211_TXCTL_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 (((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
(tx->rate->flags & IEEE80211_RATE_SHORT_PREAMBLE) &&
tx->sdata->bss_conf.use_short_preamble &&
(!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
tx->control->flags |= IEEE80211_TXCTL_SHORT_PREAMBLE;
}
/* Setup duration field for the first fragment of the frame. Duration
* for remaining fragments will be updated when they are being sent
* to low-level driver in ieee80211_tx(). */
dur = ieee80211_duration(tx, is_multicast_ether_addr(hdr->addr1),
(tx->flags & IEEE80211_TX_FRAGMENTED) ?
tx->extra_frag[0]->len : 0);
hdr->duration_id = cpu_to_le16(dur);
if ((control->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
(control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
struct ieee80211_supported_band *sband;
struct ieee80211_rate *rate, *baserate;
int idx;
sband = tx->local->hw.wiphy->bands[
tx->local->hw.conf.channel->band];
/* Do not use multiple retry rates when using RTS/CTS */
control->alt_retry_rate = NULL;
/* Use min(data rate, max base rate) as CTS/RTS rate */
rate = tx->rate;
baserate = NULL;
for (idx = 0; idx < sband->n_bitrates; idx++) {
if (sband->bitrates[idx].bitrate > rate->bitrate)
continue;
if (tx->sdata->basic_rates & BIT(idx) &&
(!baserate ||
(baserate->bitrate < sband->bitrates[idx].bitrate)))
baserate = &sband->bitrates[idx];
}
if (baserate)
control->rts_cts_rate = baserate;
else
control->rts_cts_rate = &sband->bitrates[0];
}
if (tx->sta) {
control->aid = tx->sta->aid;
tx->sta->tx_packets++;
tx->sta->tx_fragments++;
tx->sta->tx_bytes += tx->skb->len;
if (tx->extra_frag) {
int i;
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;
}
static ieee80211_tx_result
ieee80211_tx_h_load_stats(struct ieee80211_tx_data *tx)
{
struct ieee80211_local *local = tx->local;
struct sk_buff *skb = tx->skb;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u32 load = 0, hdrtime;
struct ieee80211_rate *rate = tx->rate;
/* TODO: this could be part of tx_status handling, so that the number
* of retries would be known; TX rate should in that case be stored
* somewhere with the packet */
/* Estimate total channel use caused by this frame */
/* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
* 1 usec = 1/8 * (1080 / 10) = 13.5 */
if (tx->channel->band == IEEE80211_BAND_5GHZ ||
(tx->channel->band == IEEE80211_BAND_2GHZ &&
rate->flags & IEEE80211_RATE_ERP_G))
hdrtime = CHAN_UTIL_HDR_SHORT;
else
hdrtime = CHAN_UTIL_HDR_LONG;
load = hdrtime;
if (!is_multicast_ether_addr(hdr->addr1))
load += hdrtime;
if (tx->control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
load += 2 * hdrtime;
else if (tx->control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
load += hdrtime;
/* TODO: optimise again */
load += skb->len * CHAN_UTIL_RATE_LCM / rate->bitrate;
if (tx->extra_frag) {
int i;
for (i = 0; i < tx->num_extra_frag; i++) {
load += 2 * hdrtime;
load += tx->extra_frag[i]->len *
tx->rate->bitrate;
}
}
/* Divide channel_use by 8 to avoid wrapping around the counter */
load >>= CHAN_UTIL_SHIFT;
local->channel_use_raw += load;
if (tx->sta)
tx->sta->channel_use_raw += load;
tx->sdata->channel_use_raw += load;
return TX_CONTINUE;
}
typedef ieee80211_tx_result (*ieee80211_tx_handler)(struct ieee80211_tx_data *);
static ieee80211_tx_handler ieee80211_tx_handlers[] =
{
ieee80211_tx_h_check_assoc,
ieee80211_tx_h_sequence,
ieee80211_tx_h_ps_buf,
ieee80211_tx_h_select_key,
ieee80211_tx_h_michael_mic_add,
ieee80211_tx_h_fragment,
ieee80211_tx_h_encrypt,
ieee80211_tx_h_rate_ctrl,
ieee80211_tx_h_misc,
ieee80211_tx_h_load_stats,
NULL
};
/* 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_control *control = tx->control;
sband = tx->local->hw.wiphy->bands[tx->local->hw.conf.channel->band];
control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
tx->flags |= IEEE80211_TX_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 = r;
break;
}
}
break;
case IEEE80211_RADIOTAP_ANTENNA:
/*
* radiotap uses 0 for 1st ant, mac80211 is 1 for
* 1st ant
*/
control->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)
control->flags &=
~IEEE80211_TXCTL_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_tx_control *control)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hdr *hdr;
struct ieee80211_sub_if_data *sdata;
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->control = control;
/*
* 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;
control->flags |= IEEE80211_TXCTL_NO_ACK;
} else {
tx->flags |= IEEE80211_TX_UNICAST;
control->flags &= ~IEEE80211_TXCTL_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)
tx->flags |= IEEE80211_TX_FRAGMENTED;
else
tx->flags &= ~IEEE80211_TX_FRAGMENTED;
}
if (!tx->sta)
control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
else if (tx->sta->flags & WLAN_STA_CLEAR_PS_FILT) {
control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
tx->sta->flags &= ~WLAN_STA_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];
}
control->flags |= IEEE80211_TXCTL_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_control *control)
{
struct ieee80211_tx_packet_data *pkt_data;
struct net_device *dev;
pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
dev = dev_get_by_index(&init_net, pkt_data->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, control);
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_control *control = tx->control;
int ret, i;
if (!ieee80211_qdisc_installed(local->mdev) &&
__ieee80211_queue_stopped(local, 0)) {
netif_stop_queue(local->mdev);
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, control);
if (ret)
return IEEE80211_TX_AGAIN;
local->mdev->trans_start = jiffies;
ieee80211_led_tx(local, 1);
}
if (tx->extra_frag) {
control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
IEEE80211_TXCTL_USE_CTS_PROTECT |
IEEE80211_TXCTL_CLEAR_PS_FILT |
IEEE80211_TXCTL_FIRST_FRAGMENT);
for (i = 0; i < tx->num_extra_frag; i++) {
if (!tx->extra_frag[i])
continue;
if (__ieee80211_queue_stopped(local, control->queue))
return IEEE80211_TX_FRAG_AGAIN;
if (i == tx->num_extra_frag) {
control->tx_rate = tx->last_frag_rate;
if (tx->flags & IEEE80211_TX_PROBE_LAST_FRAG)
control->flags |=
IEEE80211_TXCTL_RATE_CTRL_PROBE;
else
control->flags &=
~IEEE80211_TXCTL_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],
control);
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;
}
static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
struct ieee80211_tx_control *control)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
ieee80211_tx_handler *handler;
struct ieee80211_tx_data tx;
ieee80211_tx_result res = TX_DROP, res_prepare;
int ret, i;
WARN_ON(__ieee80211_queue_pending(local, control->queue));
if (unlikely(skb->len < 10)) {
dev_kfree_skb(skb);
return 0;
}
rcu_read_lock();
/* initialises tx */
res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control);
if (res_prepare == TX_DROP) {
dev_kfree_skb(skb);
rcu_read_unlock();
return 0;
}
sta = tx.sta;
tx.channel = local->hw.conf.channel;
for (handler = ieee80211_tx_handlers; *handler != NULL;
handler++) {
res = (*handler)(&tx);
if (res != TX_CONTINUE)
break;
}
skb = tx.skb; /* handlers are allowed to change skb */
if (unlikely(res == TX_DROP)) {
I802_DEBUG_INC(local->tx_handlers_drop);
goto drop;
}
if (unlikely(res == TX_QUEUED)) {
I802_DEBUG_INC(local->tx_handlers_queued);
rcu_read_unlock();
return 0;
}
if (tx.extra_frag) {
for (i = 0; i < tx.num_extra_frag; i++) {
int next_len, dur;
struct ieee80211_hdr *hdr =
(struct ieee80211_hdr *)
tx.extra_frag[i]->data;
if (i + 1 < tx.num_extra_frag) {
next_len = tx.extra_frag[i + 1]->len;
} else {
next_len = 0;
tx.rate = tx.last_frag_rate;
}
dur = ieee80211_duration(&tx, 0, next_len);
hdr->duration_id = cpu_to_le16(dur);
}
}
retry:
ret = __ieee80211_tx(local, skb, &tx);
if (ret) {
struct ieee80211_tx_stored_packet *store =
&local->pending_packet[control->queue];
if (ret == IEEE80211_TX_FRAG_AGAIN)
skb = NULL;
set_bit(IEEE80211_LINK_STATE_PENDING,
&local->state[control->queue]);
smp_mb();
/* When the driver gets out of buffers during sending of
* fragments and calls ieee80211_stop_queue, there is
* a small window between IEEE80211_LINK_STATE_XOFF and
* IEEE80211_LINK_STATE_PENDING flags are 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 IEEE80211_LINK_STATE_PENDING. Prevent this by
* continuing transmitting here when that situation is
* possible to have happened. */
if (!__ieee80211_queue_stopped(local, control->queue)) {
clear_bit(IEEE80211_LINK_STATE_PENDING,
&local->state[control->queue]);
goto retry;
}
memcpy(&store->control, control,
sizeof(struct ieee80211_tx_control));
store->skb = skb;
store->extra_frag = tx.extra_frag;
store->num_extra_frag = tx.num_extra_frag;
store->last_frag_rate = tx.last_frag_rate;
store->last_frag_rate_ctrl_probe =
!!(tx.flags & IEEE80211_TX_PROBE_LAST_FRAG);
}
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 */
int ieee80211_master_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ieee80211_tx_control control;
struct ieee80211_tx_packet_data *pkt_data;
struct net_device *odev = NULL;
struct ieee80211_sub_if_data *osdata;
int headroom;
int ret;
/*
* copy control out of the skb so other people can use skb->cb
*/
pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
memset(&control, 0, sizeof(struct ieee80211_tx_control));
if (pkt_data->ifindex)
odev = dev_get_by_index(&init_net, pkt_data->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);
headroom = osdata->local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM;
if (skb_headroom(skb) < headroom) {
if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) {
dev_kfree_skb(skb);
dev_put(odev);
return 0;
}
}
control.vif = &osdata->vif;
control.type = osdata->vif.type;
if (pkt_data->flags & IEEE80211_TXPD_REQ_TX_STATUS)
control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
if (pkt_data->flags & IEEE80211_TXPD_DO_NOT_ENCRYPT)
control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
if (pkt_data->flags & IEEE80211_TXPD_REQUEUE)
control.flags |= IEEE80211_TXCTL_REQUEUE;
if (pkt_data->flags & IEEE80211_TXPD_EAPOL_FRAME)
control.flags |= IEEE80211_TXCTL_EAPOL_FRAME;
if (pkt_data->flags & IEEE80211_TXPD_AMPDU)
control.flags |= IEEE80211_TXCTL_AMPDU;
control.queue = pkt_data->queue;
ret = ieee80211_tx(odev, skb, &control);
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_packet_data *pkt_data;
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;
pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
memset(pkt_data, 0, sizeof(*pkt_data));
/* needed because we set skb device to master */
pkt_data->ifindex = dev->ifindex;
pkt_data->flags |= IEEE80211_TXPD_DO_NOT_ENCRYPT;
/*
* 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_packet_data *pkt_data;
struct ieee80211_sub_if_data *sdata;
int ret = 1, head_need;
u16 ethertype, hdrlen, meshhdrlen = 0, 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)) {
printk(KERN_DEBUG "%s: short skb (len=%d)\n",
dev->name, skb->len);
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 = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
switch (sdata->vif.type) {
case IEEE80211_IF_TYPE_AP:
case IEEE80211_IF_TYPE_VLAN:
fc |= 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 |= 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 |= 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 |= 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 = sta->flags;
rcu_read_unlock();
}
/* receiver is QoS enabled, use a QoS type frame */
if (sta_flags & WLAN_STA_WME) {
fc |= 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 = cpu_to_le16(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 + local->tx_headroom;
head_need -= skb_headroom(skb);
/* We are going to modify skb data, so make a copy of it if happens to
* be cloned. This could happen, e.g., with Linux bridge code passing
* us broadcast frames. */
if (head_need > 0 || skb_header_cloned(skb)) {
#if 0
printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes "
"of headroom\n", dev->name, head_need);
#endif
if (skb_header_cloned(skb))
I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
else
I802_DEBUG_INC(local->tx_expand_skb_head);
/* Since we have to reallocate the buffer, make sure that there
* is enough room for possible WEP IV/ICV and TKIP (8 bytes
* before payload and 12 after). */
if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8),
12, GFP_ATOMIC)) {
printk(KERN_DEBUG "%s: failed to reallocate TX buffer"
"\n", dev->name);
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 (fc & IEEE80211_STYPE_QOS_DATA) {
__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;
pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
pkt_data->ifindex = dev->ifindex;
if (ethertype == ETH_P_PAE)
pkt_data->flags |= IEEE80211_TXPD_EAPOL_FRAME;
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;
}
/* helper functions for pending packets for when queues are stopped */
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
int i, j;
struct ieee80211_tx_stored_packet *store;
for (i = 0; i < local->hw.queues; i++) {
if (!__ieee80211_queue_pending(local, i))
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(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
}
}
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, reschedule = 0;
netif_tx_lock_bh(dev);
for (i = 0; i < local->hw.queues; i++) {
if (__ieee80211_queue_stopped(local, i))
continue;
if (!__ieee80211_queue_pending(local, i)) {
reschedule = 1;
continue;
}
store = &local->pending_packet[i];
tx.control = &store->control;
tx.extra_frag = store->extra_frag;
tx.num_extra_frag = store->num_extra_frag;
tx.last_frag_rate = store->last_frag_rate;
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(IEEE80211_LINK_STATE_PENDING,
&local->state[i]);
reschedule = 1;
}
}
netif_tx_unlock_bh(dev);
if (reschedule) {
if (!ieee80211_qdisc_installed(dev)) {
if (!__ieee80211_queue_stopped(local, 0))
netif_wake_queue(dev);
} else
netif_schedule(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_tx_control *control)
{
struct ieee80211_local *local = hw_to_local(hw);
struct sk_buff *skb;
struct net_device *bdev;
struct ieee80211_sub_if_data *sdata = NULL;
struct ieee80211_if_ap *ap = NULL;
struct rate_selection rsel;
struct beacon_data *beacon;
struct ieee80211_supported_band *sband;
struct ieee80211_mgmt *mgmt;
int *num_beacons;
bool err = true;
u8 *pos;
sband = local->hw.wiphy->bands[local->hw.conf.channel->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);
ieee80211_include_sequence(sdata,
(struct ieee80211_hdr *)skb->data);
/*
* 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;
err = false;
}
} 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 = IEEE80211_FC(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;
err = false;
}
if (err) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "no beacon data avail for %s\n",
bdev->name);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
skb = NULL;
goto out;
}
if (control) {
rate_control_get_rate(local->mdev, sband, skb, &rsel);
if (!rsel.rate) {
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;
}
control->vif = vif;
control->tx_rate = rsel.rate;
if (sdata->bss_conf.use_short_preamble &&
rsel.rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
control->flags |= IEEE80211_TXCTL_SHORT_PREAMBLE;
control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
control->flags |= IEEE80211_TXCTL_NO_ACK;
control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
control->retry_limit = 1;
control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
}
(*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_control *frame_txctl,
struct ieee80211_rts *rts)
{
const struct ieee80211_hdr *hdr = frame;
u16 fctl;
fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS;
rts->frame_control = cpu_to_le16(fctl);
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_control *frame_txctl,
struct ieee80211_cts *cts)
{
const struct ieee80211_hdr *hdr = frame;
u16 fctl;
fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
cts->frame_control = cpu_to_le16(fctl);
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_tx_control *control)
{
struct ieee80211_local *local = hw_to_local(hw);
struct sk_buff *skb;
struct sta_info *sta;
ieee80211_tx_handler *handler;
struct ieee80211_tx_data tx;
ieee80211_tx_result res = TX_DROP;
struct net_device *bdev;
struct ieee80211_sub_if_data *sdata;
struct ieee80211_if_ap *bss = NULL;
struct beacon_data *beacon;
sdata = vif_to_sdata(vif);
bdev = sdata->dev;
if (!bss)
return NULL;
rcu_read_lock();
beacon = rcu_dereference(bss->beacon);
if (sdata->vif.type != IEEE80211_IF_TYPE_AP || !beacon ||
!beacon->head) {
rcu_read_unlock();
return NULL;
}
if (bss->dtim_count != 0)
return NULL; /* send buffered bc/mc only after DTIM beacon */
memset(control, 0, sizeof(*control));
while (1) {
skb = skb_dequeue(&bss->ps_bc_buf);
if (!skb)
return NULL;
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, control))
break;
dev_kfree_skb_any(skb);
}
sta = tx.sta;
tx.flags |= IEEE80211_TX_PS_BUFFERED;
tx.channel = local->hw.conf.channel;
for (handler = ieee80211_tx_handlers; *handler != NULL; handler++) {
res = (*handler)(&tx);
if (res == TX_DROP || res == TX_QUEUED)
break;
}
skb = tx.skb; /* handlers are allowed to change skb */
if (res == TX_DROP) {
I802_DEBUG_INC(local->tx_handlers_drop);
dev_kfree_skb(skb);
skb = NULL;
} else if (res == TX_QUEUED) {
I802_DEBUG_INC(local->tx_handlers_queued);
skb = NULL;
}
rcu_read_unlock();
return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);
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