hostap/src/ap/ieee802_11_ht.c
Jouni Malinen baae4cb9b4 Simplify HT Capabilities element parsing
Check the element length in the parser and remove the length field from
struct ieee802_11_elems since the element is of fixed length.

Signed-off-by: Jouni Malinen <j@w1.fi>
2015-04-22 22:05:11 +03:00

490 lines
14 KiB
C

/*
* hostapd / IEEE 802.11n HT
* Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
* Copyright (c) 2007-2008, Intel Corporation
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include "utils/common.h"
#include "utils/eloop.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"
#include "hw_features.h"
#include "ap_drv_ops.h"
u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
{
struct ieee80211_ht_capabilities *cap;
u8 *pos = eid;
if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
hapd->conf->disable_11n)
return eid;
*pos++ = WLAN_EID_HT_CAP;
*pos++ = sizeof(*cap);
cap = (struct ieee80211_ht_capabilities *) pos;
os_memset(cap, 0, sizeof(*cap));
cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
16);
/* TODO: ht_extended_capabilities (now fully disabled) */
/* TODO: tx_bf_capability_info (now fully disabled) */
/* TODO: asel_capabilities (now fully disabled) */
pos += sizeof(*cap);
if (hapd->iconf->obss_interval) {
struct ieee80211_obss_scan_parameters *scan_params;
*pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
*pos++ = sizeof(*scan_params);
scan_params = (struct ieee80211_obss_scan_parameters *) pos;
os_memset(scan_params, 0, sizeof(*scan_params));
scan_params->width_trigger_scan_interval =
host_to_le16(hapd->iconf->obss_interval);
/* Fill in default values for remaining parameters
* (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
scan_params->scan_passive_dwell =
host_to_le16(20);
scan_params->scan_active_dwell =
host_to_le16(10);
scan_params->scan_passive_total_per_channel =
host_to_le16(200);
scan_params->scan_active_total_per_channel =
host_to_le16(20);
scan_params->channel_transition_delay_factor =
host_to_le16(5);
scan_params->scan_activity_threshold =
host_to_le16(25);
pos += sizeof(*scan_params);
}
return pos;
}
u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
{
struct ieee80211_ht_operation *oper;
u8 *pos = eid;
if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
return eid;
*pos++ = WLAN_EID_HT_OPERATION;
*pos++ = sizeof(*oper);
oper = (struct ieee80211_ht_operation *) pos;
os_memset(oper, 0, sizeof(*oper));
oper->primary_chan = hapd->iconf->channel;
oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
if (hapd->iconf->secondary_channel == 1)
oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
if (hapd->iconf->secondary_channel == -1)
oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
pos += sizeof(*oper);
return pos;
}
/*
op_mode
Set to 0 (HT pure) under the followign conditions
- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
Set to 1 (HT non-member protection) if there may be non-HT STAs
in both the primary and the secondary channel
Set to 2 if only HT STAs are associated in BSS,
however and at least one 20 MHz HT STA is associated
Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
*/
int hostapd_ht_operation_update(struct hostapd_iface *iface)
{
u16 cur_op_mode, new_op_mode;
int op_mode_changes = 0;
if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
return 0;
wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
__func__, iface->ht_op_mode);
if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
&& iface->num_sta_ht_no_gf) {
iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
op_mode_changes++;
} else if ((iface->ht_op_mode &
HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
iface->num_sta_ht_no_gf == 0) {
iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
op_mode_changes++;
}
if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
(iface->num_sta_no_ht || iface->olbc_ht)) {
iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
op_mode_changes++;
} else if ((iface->ht_op_mode &
HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
(iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
op_mode_changes++;
}
if (iface->num_sta_no_ht)
new_op_mode = HT_PROT_NON_HT_MIXED;
else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
new_op_mode = HT_PROT_20MHZ_PROTECTION;
else if (iface->olbc_ht)
new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
else
new_op_mode = HT_PROT_NO_PROTECTION;
cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
if (cur_op_mode != new_op_mode) {
iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
iface->ht_op_mode |= new_op_mode;
op_mode_changes++;
}
wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
__func__, iface->ht_op_mode, op_mode_changes);
return op_mode_changes;
}
static int is_40_allowed(struct hostapd_iface *iface, int channel)
{
int pri_freq, sec_freq;
int affected_start, affected_end;
int pri = 2407 + 5 * channel;
if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
return 1;
pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
if (iface->conf->secondary_channel > 0)
sec_freq = pri_freq + 20;
else
sec_freq = pri_freq - 20;
affected_start = (pri_freq + sec_freq) / 2 - 25;
affected_end = (pri_freq + sec_freq) / 2 + 25;
if ((pri < affected_start || pri > affected_end))
return 1; /* not within affected channel range */
wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
affected_start, affected_end);
wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
return 0;
}
void hostapd_2040_coex_action(struct hostapd_data *hapd,
const struct ieee80211_mgmt *mgmt, size_t len)
{
struct hostapd_iface *iface = hapd->iface;
struct ieee80211_2040_bss_coex_ie *bc_ie;
struct ieee80211_2040_intol_chan_report *ic_report;
int is_ht40_allowed = 1;
int i;
const u8 *start = (const u8 *) mgmt;
const u8 *data = start + IEEE80211_HDRLEN + 2;
hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
mgmt->u.action.u.public_action.action);
if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
return;
if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
return;
bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
bc_ie->length < 1) {
wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
bc_ie->element_id, bc_ie->length);
return;
}
if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
return;
data += 2 + bc_ie->length;
wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
bc_ie->coex_param);
if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
hostapd_logger(hapd, mgmt->sa,
HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_DEBUG,
"20 MHz BSS width request bit is set in BSS coexistence information field");
is_ht40_allowed = 0;
}
if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
hostapd_logger(hapd, mgmt->sa,
HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_DEBUG,
"40 MHz intolerant bit is set in BSS coexistence information field");
is_ht40_allowed = 0;
}
if (start + len - data >= 3 &&
data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
u8 ielen = data[1];
if (ielen > start + len - data - 2)
return;
ic_report = (struct ieee80211_2040_intol_chan_report *) data;
wpa_printf(MSG_DEBUG,
"20/40 BSS Intolerant Channel Report: Operating Class %u",
ic_report->op_class);
/* Go through the channel report to find any BSS there in the
* affected channel range */
for (i = 0; i < ielen - 1; i++) {
u8 chan = ic_report->variable[i];
if (is_40_allowed(iface, chan))
continue;
hostapd_logger(hapd, mgmt->sa,
HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_DEBUG,
"20_40_INTOLERANT channel %d reported",
chan);
is_ht40_allowed = 0;
}
}
wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
is_ht40_allowed, iface->num_sta_ht40_intolerant);
if (!is_ht40_allowed &&
(iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
if (iface->conf->secondary_channel) {
hostapd_logger(hapd, mgmt->sa,
HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_INFO,
"Switching to 20 MHz operation");
iface->conf->secondary_channel = 0;
ieee802_11_set_beacons(iface);
}
if (!iface->num_sta_ht40_intolerant &&
iface->conf->obss_interval) {
unsigned int delay_time;
delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
iface->conf->obss_interval;
eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
NULL);
eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
hapd->iface, NULL);
wpa_printf(MSG_DEBUG,
"Reschedule HT 20/40 timeout to occur in %u seconds",
delay_time);
}
}
}
u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
const u8 *ht_capab)
{
/*
* Disable HT caps for STAs associated to no-HT BSSes, or for stations
* that did not specify a valid WMM IE in the (Re)Association Request
* frame.
*/
if (!ht_capab ||
!(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
sta->flags &= ~WLAN_STA_HT;
os_free(sta->ht_capabilities);
sta->ht_capabilities = NULL;
return WLAN_STATUS_SUCCESS;
}
if (sta->ht_capabilities == NULL) {
sta->ht_capabilities =
os_zalloc(sizeof(struct ieee80211_ht_capabilities));
if (sta->ht_capabilities == NULL)
return WLAN_STATUS_UNSPECIFIED_FAILURE;
}
sta->flags |= WLAN_STA_HT;
os_memcpy(sta->ht_capabilities, ht_capab,
sizeof(struct ieee80211_ht_capabilities));
return WLAN_STATUS_SUCCESS;
}
void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
{
if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
return;
wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
" in Association Request", MAC2STR(sta->addr));
if (sta->ht40_intolerant_set)
return;
sta->ht40_intolerant_set = 1;
iface->num_sta_ht40_intolerant++;
eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
if (iface->conf->secondary_channel &&
(iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
iface->conf->secondary_channel = 0;
ieee802_11_set_beacons(iface);
}
}
void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
{
if (!sta->ht40_intolerant_set)
return;
sta->ht40_intolerant_set = 0;
iface->num_sta_ht40_intolerant--;
if (iface->num_sta_ht40_intolerant == 0 &&
(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
(iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
iface->conf->obss_interval;
wpa_printf(MSG_DEBUG,
"HT: Start 20->40 MHz transition timer (%d seconds)",
delay_time);
eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
iface, NULL);
}
}
static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
{
u16 ht_capab;
ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
"0x%04x", MAC2STR(sta->addr), ht_capab);
if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
if (!sta->no_ht_gf_set) {
sta->no_ht_gf_set = 1;
hapd->iface->num_sta_ht_no_gf++;
}
wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
"of non-gf stations %d",
__func__, MAC2STR(sta->addr),
hapd->iface->num_sta_ht_no_gf);
}
if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
if (!sta->ht_20mhz_set) {
sta->ht_20mhz_set = 1;
hapd->iface->num_sta_ht_20mhz++;
}
wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
"20MHz HT STAs %d",
__func__, MAC2STR(sta->addr),
hapd->iface->num_sta_ht_20mhz);
}
if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
ht40_intolerant_add(hapd->iface, sta);
}
static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
{
if (!sta->no_ht_set) {
sta->no_ht_set = 1;
hapd->iface->num_sta_no_ht++;
}
if (hapd->iconf->ieee80211n) {
wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
"non-HT stations %d",
__func__, MAC2STR(sta->addr),
hapd->iface->num_sta_no_ht);
}
}
void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
{
if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
update_sta_ht(hapd, sta);
else
update_sta_no_ht(hapd, sta);
if (hostapd_ht_operation_update(hapd->iface) > 0)
ieee802_11_set_beacons(hapd->iface);
}
void hostapd_get_ht_capab(struct hostapd_data *hapd,
struct ieee80211_ht_capabilities *ht_cap,
struct ieee80211_ht_capabilities *neg_ht_cap)
{
u16 cap;
if (ht_cap == NULL)
return;
os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
/*
* Mask out HT features we don't support, but don't overwrite
* non-symmetric features like STBC and SMPS. Just because
* we're not in dynamic SMPS mode the STA might still be.
*/
cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
/*
* STBC needs to be handled specially
* 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 (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
cap &= ~HT_CAP_INFO_TX_STBC;
if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
cap &= ~HT_CAP_INFO_RX_STBC_MASK;
neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
}
void ap_ht2040_timeout(void *eloop_data, void *user_data)
{
struct hostapd_iface *iface = eloop_data;
wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
iface->conf->secondary_channel = iface->secondary_ch;
ieee802_11_set_beacons(iface);
}