openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity
linux/net/mac80211/util.c

397 lines
11 KiB
C
Raw Blame History

/*
* 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.
*
* utilities for mac80211
*/
#include <net/mac80211.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/bitmap.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
#include <net/rtnetlink.h>
#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "wme.h"
/* privid for wiphys to determine whether they belong to us or not */
void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
const unsigned char rfc1042_header[] =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
const unsigned char bridge_tunnel_header[] =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
enum ieee80211_if_types type)
{
u16 fc;
/* drop ACK/CTS frames and incorrect hdr len (ctrl) */
if (len < 16)
return NULL;
fc = le16_to_cpu(hdr->frame_control);
switch (fc & IEEE80211_FCTL_FTYPE) {
case IEEE80211_FTYPE_DATA:
if (len < 24) /* drop incorrect hdr len (data) */
return NULL;
switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
case IEEE80211_FCTL_TODS:
return hdr->addr1;
case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
return NULL;
case IEEE80211_FCTL_FROMDS:
return hdr->addr2;
case 0:
return hdr->addr3;
}
break;
case IEEE80211_FTYPE_MGMT:
if (len < 24) /* drop incorrect hdr len (mgmt) */
return NULL;
return hdr->addr3;
case IEEE80211_FTYPE_CTL:
if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
return hdr->addr1;
else if ((fc & IEEE80211_FCTL_STYPE) ==
IEEE80211_STYPE_BACK_REQ) {
switch (type) {
case IEEE80211_IF_TYPE_STA:
return hdr->addr2;
case IEEE80211_IF_TYPE_AP:
case IEEE80211_IF_TYPE_VLAN:
return hdr->addr1;
default:
return NULL;
}
}
else
return NULL;
}
return NULL;
}
int ieee80211_get_hdrlen(u16 fc)
{
int hdrlen = 24;
switch (fc & IEEE80211_FCTL_FTYPE) {
case IEEE80211_FTYPE_DATA:
if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
hdrlen = 30; /* Addr4 */
/*
* The QoS Control field is two bytes and its presence is
* indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
* hdrlen if that bit is set.
* This works by masking out the bit and shifting it to
* bit position 1 so the result has the value 0 or 2.
*/
hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
>> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
break;
case IEEE80211_FTYPE_CTL:
/*
* ACK and CTS are 10 bytes, all others 16. To see how
* to get this condition consider
* subtype mask: 0b0000000011110000 (0x00F0)
* ACK subtype: 0b0000000011010000 (0x00D0)
* CTS subtype: 0b0000000011000000 (0x00C0)
* bits that matter: ^^^ (0x00E0)
* value of those: 0b0000000011000000 (0x00C0)
*/
if ((fc & 0xE0) == 0xC0)
hdrlen = 10;
else
hdrlen = 16;
break;
}
return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen);
int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
{
const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
int hdrlen;
if (unlikely(skb->len < 10))
return 0;
hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
if (unlikely(hdrlen > skb->len))
return 0;
return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
if (tx->u.tx.extra_frag) {
struct ieee80211_hdr *fhdr;
int i;
for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
fhdr = (struct ieee80211_hdr *)
tx->u.tx.extra_frag[i]->data;
fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
}
}
}
int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
int rate, int erp, int short_preamble)
{
int dur;
/* calculate duration (in microseconds, rounded up to next higher
* integer if it includes a fractional microsecond) to send frame of
* len bytes (does not include FCS) at the given rate. Duration will
* also include SIFS.
*
* rate is in 100 kbps, so divident is multiplied by 10 in the
* DIV_ROUND_UP() operations.
*/
if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {
/*
* OFDM:
*
* N_DBPS = DATARATE x 4
* N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
* (16 = SIGNAL time, 6 = tail bits)
* TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
*
* T_SYM = 4 usec
* 802.11a - 17.5.2: aSIFSTime = 16 usec
* 802.11g - 19.8.4: aSIFSTime = 10 usec +
* signal ext = 6 usec
*/
dur = 16; /* SIFS + signal ext */
dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
4 * rate); /* T_SYM x N_SYM */
} else {
/*
* 802.11b or 802.11g with 802.11b compatibility:
* 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
* Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
*
* 802.11 (DS): 15.3.3, 802.11b: 18.3.4
* aSIFSTime = 10 usec
* aPreambleLength = 144 usec or 72 usec with short preamble
* aPLCPHeaderLength = 48 usec or 24 usec with short preamble
*/
dur = 10; /* aSIFSTime = 10 usec */
dur += short_preamble ? (72 + 24) : (144 + 48);
dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
}
return dur;
}
/* Exported duration function for driver use */
__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
size_t frame_len,
struct ieee80211_rate *rate)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
u16 dur;
int erp;
erp = 0;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
sdata->bss_conf.use_short_preamble);
return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_generic_frame_duration);
__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
struct ieee80211_vif *vif, size_t frame_len,
const struct ieee80211_tx_control *frame_txctl)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
bool short_preamble;
int erp;
u16 dur;
short_preamble = sdata->bss_conf.use_short_preamble;
rate = frame_txctl->rts_cts_rate;
erp = 0;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
/* CTS duration */
dur = ieee80211_frame_duration(local, 10, rate->bitrate,
erp, short_preamble);
/* Data frame duration */
dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
erp, short_preamble);
/* ACK duration */
dur += ieee80211_frame_duration(local, 10, rate->bitrate,
erp, short_preamble);
return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_rts_duration);
__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
size_t frame_len,
const struct ieee80211_tx_control *frame_txctl)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
bool short_preamble;
int erp;
u16 dur;
short_preamble = sdata->bss_conf.use_short_preamble;
rate = frame_txctl->rts_cts_rate;
erp = 0;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
/* Data frame duration */
dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
erp, short_preamble);
if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
/* ACK duration */
dur += ieee80211_frame_duration(local, 10, rate->bitrate,
erp, short_preamble);
}
return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_ctstoself_duration);
void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
{
struct ieee80211_local *local = hw_to_local(hw);
if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
&local->state[queue])) {
if (test_bit(IEEE80211_LINK_STATE_PENDING,
&local->state[queue]))
tasklet_schedule(&local->tx_pending_tasklet);
else
if (!ieee80211_qdisc_installed(local->mdev)) {
if (queue == 0)
netif_wake_queue(local->mdev);
} else
__netif_schedule(local->mdev);
}
}
EXPORT_SYMBOL(ieee80211_wake_queue);
void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
{
struct ieee80211_local *local = hw_to_local(hw);
if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
netif_stop_queue(local->mdev);
set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
}
EXPORT_SYMBOL(ieee80211_stop_queue);
void ieee80211_start_queues(struct ieee80211_hw *hw)
{
struct ieee80211_local *local = hw_to_local(hw);
int i;
for (i = 0; i < local->hw.queues; i++)
clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
if (!ieee80211_qdisc_installed(local->mdev))
netif_start_queue(local->mdev);
}
EXPORT_SYMBOL(ieee80211_start_queues);
void ieee80211_stop_queues(struct ieee80211_hw *hw)
{
int i;
for (i = 0; i < hw->queues; i++)
ieee80211_stop_queue(hw, i);
}
EXPORT_SYMBOL(ieee80211_stop_queues);
void ieee80211_wake_queues(struct ieee80211_hw *hw)
{
int i;
for (i = 0; i < hw->queues; i++)
ieee80211_wake_queue(hw, i);
}
EXPORT_SYMBOL(ieee80211_wake_queues);
void ieee80211_iterate_active_interfaces(
struct ieee80211_hw *hw,
void (*iterator)(void *data, u8 *mac,
struct ieee80211_vif *vif),
void *data)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
rcu_read_lock();
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
switch (sdata->vif.type) {
case IEEE80211_IF_TYPE_INVALID:
case IEEE80211_IF_TYPE_MNTR:
case IEEE80211_IF_TYPE_VLAN:
continue;
case IEEE80211_IF_TYPE_AP:
case IEEE80211_IF_TYPE_STA:
case IEEE80211_IF_TYPE_IBSS:
case IEEE80211_IF_TYPE_WDS:
break;
}
if (sdata->dev == local->mdev)
continue;
if (netif_running(sdata->dev))
iterator(data, sdata->dev->dev_addr,
&sdata->vif);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
Reference in New Issue View Git Blame Copy Permalink