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hostapd: Add Transmit Power Envelope IE when VHT is enabled

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Add Transmit Power Envelope element defined in IEEE P802.11-REVmc/D4.3,
8.4.2.161.

Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
This commit is contained in:
Rajkumar Manoharan 2015-11-23 18:40:26 +05:30 committed by Jouni Malinen
parent 7767687109
commit 3c417499e7
3 changed files with 116 additions and 0 deletions
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2
src/ap/beacon.c
View file

@ -481,6 +481,7 @@ static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
if (hapd->iconf->ieee80211ac && !hapd->conf->disable_11ac) {
pos = hostapd_eid_vht_capabilities(hapd, pos);
pos = hostapd_eid_vht_operation(hapd, pos);
pos = hostapd_eid_txpower_envelope(hapd, pos);
pos = hostapd_eid_wb_chsw_wrapper(hapd, pos);
}
if (hapd->conf->vendor_vht)
@ -1096,6 +1097,7 @@ int ieee802_11_build_ap_params(struct hostapd_data *hapd,
if (hapd->iconf->ieee80211ac && !hapd->conf->disable_11ac) {
tailpos = hostapd_eid_vht_capabilities(hapd, tailpos);
tailpos = hostapd_eid_vht_operation(hapd, tailpos);
tailpos = hostapd_eid_txpower_envelope(hapd, tailpos);
tailpos = hostapd_eid_wb_chsw_wrapper(hapd, tailpos);
}
if (hapd->conf->vendor_vht)

1
src/ap/ieee802_11.h
View file

@ -54,6 +54,7 @@ u8 * hostapd_eid_vht_capabilities(struct hostapd_data *hapd, u8 *eid);
u8 * hostapd_eid_vht_operation(struct hostapd_data *hapd, u8 *eid);
u8 * hostapd_eid_vendor_vht(struct hostapd_data *hapd, u8 *eid);
u8 * hostapd_eid_wb_chsw_wrapper(struct hostapd_data *hapd, u8 *eid);
u8 * hostapd_eid_txpower_envelope(struct hostapd_data *hapd, u8 *eid);
int hostapd_ht_operation_update(struct hostapd_iface *iface);
void ieee802_11_send_sa_query_req(struct hostapd_data *hapd,

113
src/ap/ieee802_11_vht.c
View file

@ -17,6 +17,7 @@
#include "sta_info.h"
#include "beacon.h"
#include "ieee802_11.h"
#include "dfs.h"
u8 * hostapd_eid_vht_capabilities(struct hostapd_data *hapd, u8 *eid)
@ -184,6 +185,118 @@ u8 * hostapd_eid_wb_chsw_wrapper(struct hostapd_data *hapd, u8 *eid)
}
u8 * hostapd_eid_txpower_envelope(struct hostapd_data *hapd, u8 *eid)
{
struct hostapd_iface *iface = hapd->iface;
struct hostapd_config *iconf = iface->conf;
struct hostapd_hw_modes *mode = iface->current_mode;
struct hostapd_channel_data *chan;
int dfs, i;
u8 channel, tx_pwr_count, local_pwr_constraint;
int max_tx_power;
u8 tx_pwr;
if (!mode)
return eid;
if (ieee80211_freq_to_chan(iface->freq, &channel) == NUM_HOSTAPD_MODES)
return eid;
for (i = 0; i < mode->num_channels; i++) {
if (mode->channels[i].freq == iface->freq)
break;
}
if (i == mode->num_channels)
return eid;
switch (iface->conf->vht_oper_chwidth) {
case VHT_CHANWIDTH_USE_HT:
if (iconf->secondary_channel == 0) {
/* Max Transmit Power count = 0 (20 MHz) */
tx_pwr_count = 0;
} else {
/* Max Transmit Power count = 1 (20, 40 MHz) */
tx_pwr_count = 1;
}
break;
case VHT_CHANWIDTH_80MHZ:
/* Max Transmit Power count = 2 (20, 40, and 80 MHz) */
tx_pwr_count = 2;
break;
case VHT_CHANWIDTH_80P80MHZ:
case VHT_CHANWIDTH_160MHZ:
/* Max Transmit Power count = 3 (20, 40, 80, 160/80+80 MHz) */
tx_pwr_count = 3;
break;
default:
return eid;
}
/*
* Below local_pwr_constraint logic is referred from
* hostapd_eid_pwr_constraint.
*
* Check if DFS is required by regulatory.
*/
dfs = hostapd_is_dfs_required(hapd->iface);
if (dfs < 0)
dfs = 0;
/*
* In order to meet regulations when TPC is not implemented using
* a transmit power that is below the legal maximum (including any
* mitigation factor) should help. In this case, indicate 3 dB below
* maximum allowed transmit power.
*/
if (hapd->iconf->local_pwr_constraint == -1)
local_pwr_constraint = (dfs == 0) ? 0 : 3;
else
local_pwr_constraint = hapd->iconf->local_pwr_constraint;
/*
* A STA that is not an AP shall use a transmit power less than or
* equal to the local maximum transmit power level for the channel.
* The local maximum transmit power can be calculated from the formula:
* local max TX pwr = max TX pwr - local pwr constraint
* Where max TX pwr is maximum transmit power level specified for
* channel in Country element and local pwr constraint is specified
* for channel in this Power Constraint element.
*/
chan = &mode->channels[i];
max_tx_power = chan->max_tx_power - local_pwr_constraint;
/*
* Local Maximum Transmit power is encoded as two's complement
* with a 0.5 dB step.
*/
max_tx_power *= 2; /* in 0.5 dB steps */
if (max_tx_power > 127) {
/* 63.5 has special meaning of 63.5 dBm or higher */
max_tx_power = 127;
}
if (max_tx_power < -128)
max_tx_power = -128;
if (max_tx_power < 0)
tx_pwr = 0x80 + max_tx_power + 128;
else
tx_pwr = max_tx_power;
*eid++ = WLAN_EID_VHT_TRANSMIT_POWER_ENVELOPE;
*eid++ = 2 + tx_pwr_count;
/*
* Max Transmit Power count and
* Max Transmit Power units = 0 (EIRP)
*/
*eid++ = tx_pwr_count;
for (i = 0; i <= tx_pwr_count; i++)
*eid++ = tx_pwr;
return eid;
}
u16 copy_sta_vht_capab(struct hostapd_data *hapd, struct sta_info *sta,
const u8 *vht_capab)
{