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alistair23-linux/net/mac80211/util.c
Johannes Berg 8318d78a44 cfg80211 API for channels/bitrates, mac80211 and driver conversion 
This patch creates new cfg80211 wiphy API for channel and bitrate
registration and converts mac80211 and drivers to the new API. The
old mac80211 API is completely ripped out. All drivers (except ath5k)
are updated to the new API, in many cases I expect that optimisations
can be done.

Along with the regulatory code I've also ripped out the
IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED flag, I believe it to be
unnecessary if the hardware simply gives us whatever channels it wants
to support and we then enable/disable them as required, which is pretty
much required for travelling.

Additionally, the patch adds proper "basic" rate handling for STA
mode interface, AP mode interface will have to have new API added
to allow userspace to set the basic rate set, currently it'll be
empty... However, the basic rate handling will need to be moved to
the BSS conf stuff.

I do expect there to be bugs in this, especially wrt. transmit
power handling where I'm basically clueless about how it should work.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-02-29 15:19:32 -05:00

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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.
*
* 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);
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