Add Transmit Power Envelope element defined in
IEEE P802.11-REVmc/D4.3, 8.4.2.161.
Signed-off-by: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxxxx>
---
v2:
* "VHT" removed from the name
* removed channel switch conditions
* handled 80+80/160 MHz case
* corrected max tx power calculation
src/ap/beacon.c | 2 +
src/ap/ieee802_11.h | 1 +
src/ap/ieee802_11_vht.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 106 insertions(+)
diff --git a/src/ap/beacon.c b/src/ap/beacon.c
index 5f65b7d..d4054cb 100644
--- a/src/ap/beacon.c
+++ b/src/ap/beacon.c
@@ -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_vht_txpwr_env(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_vht_txpwr_env(hapd, tailpos);
tailpos = hostapd_eid_wb_chsw_wrapper(hapd, tailpos);
}
if (hapd->conf->vendor_vht)
diff --git a/src/ap/ieee802_11.h b/src/ap/ieee802_11.h
index a2dd132..4788e6b 100644
--- a/src/ap/ieee802_11.h
+++ b/src/ap/ieee802_11.h
@@ -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_vht_txpwr_env(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,
diff --git a/src/ap/ieee802_11_vht.c b/src/ap/ieee802_11_vht.c
index 8d2c428..59522a7 100644
--- a/src/ap/ieee802_11_vht.c
+++ b/src/ap/ieee802_11_vht.c
@@ -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 +185,108 @@ u8 * hostapd_eid_wb_chsw_wrapper(struct hostapd_data *hapd, u8 *eid)
}
+u8 * hostapd_eid_vht_txpwr_env(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, max_tx_power, tx_pwr_count, local_pwr_constraint;
+
+ 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 (20MHz) */
+ tx_pwr_count = 0;
+ } else {
+ /* Max Transmit Power count = 1 (20, 40MHz) */
+ tx_pwr_count = 1;
+ }
+ break;
+ case VHT_CHANWIDTH_80MHZ:
+ /* Max Transmit Power count = 2 (20, 40 and 80MHz) */
+ tx_pwr_count = 2;
+ break;
+ case VHT_CHANWIDTH_80P80MHZ:
+ case VHT_CHANWIDTH_160MHZ:
+ /* Max Transmit Power count = 3 (20, 40, 80, 160/80+80MHz) */
+ 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 2's complement
+ * with a 0.5 dB step
+ */
+ max_tx_power = ~(max_tx_power * 2) + 1;
+
+ *eid++ = WLAN_EID_VHT_TRANSMIT_POWER_ENVELOPE;
+ *eid++ = 4;
+
+ /*
+ * Max Transmit Power count and
+ * Max Transmit Power units = 0 (EIRP)
+ */
+ *eid++ = tx_pwr_count;
+
+ i = 0;
+ while (i++ <= tx_pwr_count)
+ *eid++ = max_tx_power;
+
+ return eid;
+}
+
+
u16 copy_sta_vht_capab(struct hostapd_data *hapd, struct sta_info *sta,
const u8 *vht_capab)
{
--
2.6.2
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