src/ap/ieee802_11_vht.c

/*
 * hostapd / IEEE 802.11ac VHT
 * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of BSD license
 *
 * See README and COPYING for more details.
 */

#include "utils/includes.h"

#include "utils/common.h"
#include "common/ieee802_11_defs.h"
#include "hostapd.h"
#include "ap_config.h"
#include "sta_info.h"
#include "beacon.h"
#include "ieee802_11.h"


u8 * hostapd_eid_vht_capabilities(struct hostapd_data *hapd, u8 *eid)
{
	struct ieee80211_vht_capabilities *cap;
	struct hostapd_hw_modes *mode = hapd->iface->current_mode;
	u8 *pos = eid;

	if (!mode)
		return eid;

	if (mode->mode == HOSTAPD_MODE_IEEE80211G && hapd->conf->vendor_vht &&
	    mode->vht_capab == 0 && hapd->iface->hw_features) {
		int i;

		for (i = 0; i < hapd->iface->num_hw_features; i++) {
			if (hapd->iface->hw_features[i].mode ==
			    HOSTAPD_MODE_IEEE80211A) {
				mode = &hapd->iface->hw_features[i];
				break;
			}
		}
	}

	*pos++ = WLAN_EID_VHT_CAP;
	*pos++ = sizeof(*cap);

	cap = (struct ieee80211_vht_capabilities *) pos;
	os_memset(cap, 0, sizeof(*cap));
	cap->vht_capabilities_info = host_to_le32(
		hapd->iface->conf->vht_capab);

	/* Supported MCS set comes from hw */
	os_memcpy(&cap->vht_supported_mcs_set, mode->vht_mcs_set, 8);

	pos += sizeof(*cap);

	return pos;
}


u8 * hostapd_eid_vht_operation(struct hostapd_data *hapd, u8 *eid)
{
	struct ieee80211_vht_operation *oper;
	u8 *pos = eid;

	*pos++ = WLAN_EID_VHT_OPERATION;
	*pos++ = sizeof(*oper);

	oper = (struct ieee80211_vht_operation *) pos;
	os_memset(oper, 0, sizeof(*oper));

	/*
	 * center freq = 5 GHz + (5 * index)
	 * So index 42 gives center freq 5.210 GHz
	 * which is channel 42 in 5G band
	 */
	oper->vht_op_info_chan_center_freq_seg0_idx =
		hapd->iconf->vht_oper_centr_freq_seg0_idx;
	oper->vht_op_info_chan_center_freq_seg1_idx =
		hapd->iconf->vht_oper_centr_freq_seg1_idx;

	oper->vht_op_info_chwidth = hapd->iconf->vht_oper_chwidth;

	/* VHT Basic MCS set comes from hw */
	/* Hard code 1 stream, MCS0-7 is a min Basic VHT MCS rates */
	oper->vht_basic_mcs_set = host_to_le16(0xfffc);
	pos += sizeof(*oper);

	return pos;
}


static int check_valid_vht_mcs(struct hostapd_hw_modes *mode,
			       const u8 *sta_vht_capab)
{
	const struct ieee80211_vht_capabilities *vht_cap;
	struct ieee80211_vht_capabilities ap_vht_cap;
	u16 sta_rx_mcs_set, ap_tx_mcs_set;
	int i;

	if (!mode)
		return 1;

	/*
	 * Disable VHT caps for STAs for which there is not even a single
	 * allowed MCS in any supported number of streams, i.e., STA is
	 * advertising 3 (not supported) as VHT MCS rates for all supported
	 * stream cases.
	 */
	os_memcpy(&ap_vht_cap.vht_supported_mcs_set, mode->vht_mcs_set,
		  sizeof(ap_vht_cap.vht_supported_mcs_set));
	vht_cap = (const struct ieee80211_vht_capabilities *) sta_vht_capab;

	/* AP Tx MCS map vs. STA Rx MCS map */
	sta_rx_mcs_set = le_to_host16(vht_cap->vht_supported_mcs_set.rx_map);
	ap_tx_mcs_set = le_to_host16(ap_vht_cap.vht_supported_mcs_set.tx_map);

	for (i = 0; i < VHT_RX_NSS_MAX_STREAMS; i++) {
		if ((ap_tx_mcs_set & (0x3 << (i * 2))) == 3)
			continue;

		if ((sta_rx_mcs_set & (0x3 << (i * 2))) == 3)
			continue;

		return 1;
	}

	wpa_printf(MSG_DEBUG,
		   "No matching VHT MCS found between AP TX and STA RX");
	return 0;
}


u16 copy_sta_vht_capab(struct hostapd_data *hapd, struct sta_info *sta,
		       const u8 *vht_capab, size_t vht_capab_len)
{
	/* Disable VHT caps for STAs associated to no-VHT BSSes. */
	if (!vht_capab ||
	    vht_capab_len < sizeof(struct ieee80211_vht_capabilities) ||
	    hapd->conf->disable_11ac ||
	    !check_valid_vht_mcs(hapd->iface->current_mode, vht_capab)) {
		sta->flags &= ~WLAN_STA_VHT;
		os_free(sta->vht_capabilities);
		sta->vht_capabilities = NULL;
		return WLAN_STATUS_SUCCESS;
	}

	if (sta->vht_capabilities == NULL) {
		sta->vht_capabilities =
			os_zalloc(sizeof(struct ieee80211_vht_capabilities));
		if (sta->vht_capabilities == NULL)
			return WLAN_STATUS_UNSPECIFIED_FAILURE;
	}

	sta->flags |= WLAN_STA_VHT;
	os_memcpy(sta->vht_capabilities, vht_capab,
		  sizeof(struct ieee80211_vht_capabilities));

	return WLAN_STATUS_SUCCESS;
}


u16 copy_sta_vendor_vht(struct hostapd_data *hapd, struct sta_info *sta,
			const u8 *ie, size_t len)
{
	const u8 *vht_capab;
	unsigned int vht_capab_len;

	if (!ie || len < 5 + 2 + sizeof(struct ieee80211_vht_capabilities) ||
	    hapd->conf->disable_11ac)
		goto no_capab;

	/* The VHT Capabilities element embedded in vendor VHT */
	vht_capab = ie + 5;
	if (vht_capab[0] != WLAN_EID_VHT_CAP)
		goto no_capab;
	vht_capab_len = vht_capab[1];
	if (vht_capab_len < sizeof(struct ieee80211_vht_capabilities) ||
	    (int) vht_capab_len > ie + len - vht_capab - 2)
		goto no_capab;
	vht_capab += 2;

	if (sta->vht_capabilities == NULL) {
		sta->vht_capabilities =
			os_zalloc(sizeof(struct ieee80211_vht_capabilities));
		if (sta->vht_capabilities == NULL)
			return WLAN_STATUS_UNSPECIFIED_FAILURE;
	}

	sta->flags |= WLAN_STA_VHT | WLAN_STA_VENDOR_VHT;
	os_memcpy(sta->vht_capabilities, vht_capab,
		  sizeof(struct ieee80211_vht_capabilities));
	return WLAN_STATUS_SUCCESS;

no_capab:
	sta->flags &= ~WLAN_STA_VENDOR_VHT;
	return WLAN_STATUS_SUCCESS;
}


u8 * hostapd_eid_vendor_vht(struct hostapd_data *hapd, u8 *eid)
{
	u8 *pos = eid;

	if (!hapd->iface->current_mode)
		return eid;

	*pos++ = WLAN_EID_VENDOR_SPECIFIC;
	*pos++ = (5 +		/* The Vendor OUI, type and subtype */
		  2 + sizeof(struct ieee80211_vht_capabilities) +
		  2 + sizeof(struct ieee80211_vht_operation));

	WPA_PUT_BE32(pos, (OUI_BROADCOM << 8) | VENDOR_VHT_TYPE);
	pos += 4;
	*pos++ = VENDOR_VHT_SUBTYPE;
	pos = hostapd_eid_vht_capabilities(hapd, pos);
	pos = hostapd_eid_vht_operation(hapd, pos);

	return pos;
}


u16 set_sta_vht_opmode(struct hostapd_data *hapd, struct sta_info *sta,
		       const u8 *vht_oper_notif)
{
	if (!vht_oper_notif) {
		sta->flags &= ~WLAN_STA_VHT_OPMODE_ENABLED;
		return WLAN_STATUS_SUCCESS;
	}

	sta->flags |= WLAN_STA_VHT_OPMODE_ENABLED;
	sta->vht_opmode = *vht_oper_notif;
	return WLAN_STATUS_SUCCESS;
}


void hostapd_get_vht_capab(struct hostapd_data *hapd,
			   struct ieee80211_vht_capabilities *vht_cap,
			   struct ieee80211_vht_capabilities *neg_vht_cap)
{
	u32 cap, own_cap, sym_caps;

	if (vht_cap == NULL)
		return;
	os_memcpy(neg_vht_cap, vht_cap, sizeof(*neg_vht_cap));

	cap = le_to_host32(neg_vht_cap->vht_capabilities_info);
	own_cap = hapd->iconf->vht_capab;

	/* mask out symmetric VHT capabilities we don't support */
	sym_caps = VHT_CAP_SHORT_GI_80 | VHT_CAP_SHORT_GI_160;
	cap &= ~sym_caps | (own_cap & sym_caps);

	/* mask out beamformer/beamformee caps if not supported */
	if (!(own_cap & VHT_CAP_SU_BEAMFORMER_CAPABLE))
		cap &= ~(VHT_CAP_SU_BEAMFORMEE_CAPABLE |
			 VHT_CAP_BEAMFORMEE_STS_MAX);

	if (!(own_cap & VHT_CAP_SU_BEAMFORMEE_CAPABLE))
		cap &= ~(VHT_CAP_SU_BEAMFORMER_CAPABLE |
			 VHT_CAP_SOUNDING_DIMENSION_MAX);

	if (!(own_cap & VHT_CAP_MU_BEAMFORMER_CAPABLE))
		cap &= ~VHT_CAP_MU_BEAMFORMEE_CAPABLE;

	if (!(own_cap & VHT_CAP_MU_BEAMFORMEE_CAPABLE))
		cap &= ~VHT_CAP_MU_BEAMFORMER_CAPABLE;

	/* mask channel widths we don't support */
	switch (own_cap & VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
	case VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
		break;
	case VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
		if (cap & VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ) {
			cap &= ~VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ;
			cap |= VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
		}
		break;
	default:
		cap &= ~VHT_CAP_SUPP_CHAN_WIDTH_MASK;
		break;
	}

	if (!(cap & VHT_CAP_SUPP_CHAN_WIDTH_MASK))
		cap &= ~VHT_CAP_SHORT_GI_160;

	/*
	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
	 */
	if (!(own_cap & VHT_CAP_RXSTBC_MASK))
		cap &= ~VHT_CAP_TXSTBC;
	if (!(own_cap & VHT_CAP_TXSTBC))
		cap &= ~VHT_CAP_RXSTBC_MASK;

	neg_vht_cap->vht_capabilities_info = host_to_le32(cap);
}