hostap/hostapd/hw_features.c
Jouni Malinen ad1e68e6b5 Clean up HT40 scan and share nl80211 scanning code
Instead of adding a new driver_ops for fetching neighbor BSS data (that
nl80211 driver interface had to scan during initialization), share the
same scan operations that wpa_supplicant is using. This gets rid of
duplicated scan code in driver_nl80211.c (and better yet, removes large
part of old WEXT code).

hostapd interface initialization is now completed in a callback, if
needed, i.e., he_features channel/hw_mode selection can use as much time
as needed. This can also help with radar detection in the future.
2009-04-16 16:22:40 +03:00

725 lines
19 KiB
C

/*
* hostapd / Hardware feature query and different modes
* Copyright 2002-2003, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright (c) 2008, Jouni Malinen <j@w1.fi>
*
* 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.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "hostapd.h"
#include "ieee802_11_defs.h"
#include "ieee802_11_common.h"
#include "eloop.h"
#include "hw_features.h"
#include "driver_i.h"
#include "config.h"
void hostapd_free_hw_features(struct hostapd_hw_modes *hw_features,
size_t num_hw_features)
{
size_t i;
if (hw_features == NULL)
return;
for (i = 0; i < num_hw_features; i++) {
os_free(hw_features[i].channels);
os_free(hw_features[i].rates);
}
os_free(hw_features);
}
int hostapd_get_hw_features(struct hostapd_iface *iface)
{
struct hostapd_data *hapd = iface->bss[0];
int ret = 0, i, j;
u16 num_modes, flags;
struct hostapd_hw_modes *modes;
if (hostapd_drv_none(hapd))
return -1;
modes = hostapd_get_hw_feature_data(hapd, &num_modes, &flags);
if (modes == NULL) {
hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_DEBUG,
"Fetching hardware channel/rate support not "
"supported.");
return -1;
}
iface->hw_flags = flags;
hostapd_free_hw_features(iface->hw_features, iface->num_hw_features);
iface->hw_features = modes;
iface->num_hw_features = num_modes;
for (i = 0; i < num_modes; i++) {
struct hostapd_hw_modes *feature = &modes[i];
/* set flag for channels we can use in current regulatory
* domain */
for (j = 0; j < feature->num_channels; j++) {
/*
* Disable all channels that are marked not to allow
* IBSS operation or active scanning. In addition,
* disable all channels that require radar detection,
* since that (in addition to full DFS) is not yet
* supported.
*/
if (feature->channels[j].flag &
(HOSTAPD_CHAN_NO_IBSS |
HOSTAPD_CHAN_PASSIVE_SCAN |
HOSTAPD_CHAN_RADAR))
feature->channels[j].flag |=
HOSTAPD_CHAN_DISABLED;
if (feature->channels[j].flag & HOSTAPD_CHAN_DISABLED)
continue;
wpa_printf(MSG_MSGDUMP, "Allowed channel: mode=%d "
"chan=%d freq=%d MHz max_tx_power=%d dBm",
feature->mode,
feature->channels[j].chan,
feature->channels[j].freq,
feature->channels[j].max_tx_power);
}
}
return ret;
}
static int hostapd_prepare_rates(struct hostapd_data *hapd,
struct hostapd_hw_modes *mode)
{
int i, num_basic_rates = 0;
int basic_rates_a[] = { 60, 120, 240, -1 };
int basic_rates_b[] = { 10, 20, -1 };
int basic_rates_g[] = { 10, 20, 55, 110, -1 };
int *basic_rates;
if (hapd->iconf->basic_rates)
basic_rates = hapd->iconf->basic_rates;
else switch (mode->mode) {
case HOSTAPD_MODE_IEEE80211A:
basic_rates = basic_rates_a;
break;
case HOSTAPD_MODE_IEEE80211B:
basic_rates = basic_rates_b;
break;
case HOSTAPD_MODE_IEEE80211G:
basic_rates = basic_rates_g;
break;
default:
return -1;
}
if (hostapd_set_rate_sets(hapd, hapd->iconf->supported_rates,
basic_rates, mode->mode)) {
wpa_printf(MSG_ERROR, "Failed to update rate sets in kernel "
"module");
}
os_free(hapd->iface->current_rates);
hapd->iface->num_rates = 0;
hapd->iface->current_rates =
os_malloc(mode->num_rates * sizeof(struct hostapd_rate_data));
if (!hapd->iface->current_rates) {
wpa_printf(MSG_ERROR, "Failed to allocate memory for rate "
"table.");
return -1;
}
for (i = 0; i < mode->num_rates; i++) {
struct hostapd_rate_data *rate;
if (hapd->iconf->supported_rates &&
!hostapd_rate_found(hapd->iconf->supported_rates,
mode->rates[i].rate))
continue;
rate = &hapd->iface->current_rates[hapd->iface->num_rates];
os_memcpy(rate, &mode->rates[i],
sizeof(struct hostapd_rate_data));
if (hostapd_rate_found(basic_rates, rate->rate)) {
rate->flags |= HOSTAPD_RATE_BASIC;
num_basic_rates++;
} else
rate->flags &= ~HOSTAPD_RATE_BASIC;
wpa_printf(MSG_DEBUG, "RATE[%d] rate=%d flags=0x%x",
hapd->iface->num_rates, rate->rate, rate->flags);
hapd->iface->num_rates++;
}
if (hapd->iface->num_rates == 0 || num_basic_rates == 0) {
wpa_printf(MSG_ERROR, "No rates remaining in supported/basic "
"rate sets (%d,%d).",
hapd->iface->num_rates, num_basic_rates);
return -1;
}
return 0;
}
#ifdef CONFIG_IEEE80211N
static int ieee80211n_allowed_ht40_channel_pair(struct hostapd_iface *iface)
{
int sec_chan, ok, j, first;
int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
184, 192 };
size_t k;
if (!iface->conf->secondary_channel)
return 1; /* HT40 not used */
sec_chan = iface->conf->channel + iface->conf->secondary_channel * 4;
wpa_printf(MSG_DEBUG, "HT40: control channel: %d "
"secondary channel: %d",
iface->conf->channel, sec_chan);
/* Verify that HT40 secondary channel is an allowed 20 MHz
* channel */
ok = 0;
for (j = 0; j < iface->current_mode->num_channels; j++) {
struct hostapd_channel_data *chan =
&iface->current_mode->channels[j];
if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
chan->chan == sec_chan) {
ok = 1;
break;
}
}
if (!ok) {
wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
sec_chan);
return 0;
}
/*
* Verify that HT40 primary,secondary channel pair is allowed per
* IEEE 802.11n Annex J. This is only needed for 5 GHz band since
* 2.4 GHz rules allow all cases where the secondary channel fits into
* the list of allowed channels (already checked above).
*/
if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
return 1;
if (iface->conf->secondary_channel > 0)
first = iface->conf->channel;
else
first = sec_chan;
ok = 0;
for (k = 0; k < sizeof(allowed) / sizeof(allowed[0]); k++) {
if (first == allowed[k]) {
ok = 1;
break;
}
}
if (!ok) {
wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
iface->conf->channel,
iface->conf->secondary_channel);
return 0;
}
return 1;
}
static void ieee80211n_switch_pri_sec(struct hostapd_iface *iface)
{
if (iface->conf->secondary_channel > 0) {
iface->conf->channel += 4;
iface->conf->secondary_channel = -1;
} else {
iface->conf->channel -= 4;
iface->conf->secondary_channel = 1;
}
}
static void ieee80211n_get_pri_sec_chan(struct wpa_scan_res *bss,
int *pri_chan, int *sec_chan)
{
struct ieee80211_ht_operation *oper;
struct ieee802_11_elems elems;
*pri_chan = *sec_chan = 0;
ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
if (elems.ht_operation &&
elems.ht_operation_len >= sizeof(*oper)) {
oper = (struct ieee80211_ht_operation *) elems.ht_operation;
*pri_chan = oper->control_chan;
if (oper->ht_param & HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH) {
if (oper->ht_param &
HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
*sec_chan = *pri_chan + 4;
else if (oper->ht_param &
HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
*sec_chan = *pri_chan - 4;
}
}
}
static int ieee80211n_check_40mhz_5g(struct hostapd_iface *iface,
struct wpa_scan_results *scan_res)
{
int pri_chan, sec_chan, pri_freq, sec_freq, pri_bss, sec_bss;
int bss_pri_chan, bss_sec_chan;
size_t i;
int match;
pri_chan = iface->conf->channel;
sec_chan = iface->conf->secondary_channel * 4;
pri_freq = hostapd_hw_get_freq(iface->bss[0], pri_chan);
if (iface->conf->secondary_channel > 0)
sec_freq = pri_freq + 20;
else
sec_freq = pri_freq - 20;
/*
* Switch PRI/SEC channels if Beacons were detected on selected SEC
* channel, but not on selected PRI channel.
*/
pri_bss = sec_bss = 0;
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
if (bss->freq == pri_freq)
pri_bss++;
else if (bss->freq == sec_freq)
sec_bss++;
}
if (sec_bss && !pri_bss) {
wpa_printf(MSG_INFO, "Switch own primary and secondary "
"channel to get secondary channel with no Beacons "
"from other BSSes");
ieee80211n_switch_pri_sec(iface);
}
/*
* Match PRI/SEC channel with any existing HT40 BSS on the same
* channels that we are about to use (if already mixed order in
* existing BSSes, use own preference).
*/
match = 0;
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
if (pri_chan == bss_pri_chan &&
sec_chan == bss_sec_chan) {
match = 1;
break;
}
}
if (!match) {
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
ieee80211n_get_pri_sec_chan(bss, &pri_chan, &sec_chan);
if (pri_chan == bss_sec_chan &&
sec_chan == bss_pri_chan) {
wpa_printf(MSG_INFO, "Switch own primary and "
"secondary channel due to BSS "
"overlap with " MACSTR,
MAC2STR(bss->bssid));
ieee80211n_switch_pri_sec(iface);
break;
}
}
}
return 1;
}
static int ieee80211n_check_40mhz_2g4(struct hostapd_iface *iface,
struct wpa_scan_results *scan_res)
{
int pri_freq, sec_freq;
int affected_start, affected_end;
size_t i;
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;
wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
affected_start, affected_end);
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
int pri = bss->freq;
int sec = pri;
int sec_chan, pri_chan;
ieee80211n_get_pri_sec_chan(bss, &pri_chan, &sec_chan);
if (sec_chan) {
if (sec_chan < pri_chan)
sec = pri - 20;
else
sec = pri + 20;
}
if ((pri < affected_start || pri > affected_end) &&
(sec < affected_start || sec > affected_end))
continue; /* not within affected channel range */
wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
" freq=%d pri=%d sec=%d",
MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
if (sec_chan) {
if (pri_freq != pri || sec_freq != sec) {
wpa_printf(MSG_DEBUG, "40 MHz pri/sec "
"mismatch with BSS " MACSTR
" <%d,%d> (chan=%d%c) vs. <%d,%d>",
MAC2STR(bss->bssid),
pri, sec, pri_chan,
sec > pri ? '+' : '-',
pri_freq, sec_freq);
return 0;
}
}
/* TODO: 40 MHz intolerant */
}
return 1;
}
static void ieee80211n_check_scan(struct hostapd_iface *iface)
{
struct wpa_scan_results *scan_res;
int oper40;
/* Check list of neighboring BSSes (from scan) to see whether 40 MHz is
* allowed per IEEE 802.11n/D7.0, 11.14.3.2 */
iface->scan_cb = NULL;
scan_res = hostapd_driver_get_scan_results(iface->bss[0]);
if (scan_res == NULL) {
hostapd_setup_interface_complete(iface, 1);
return;
}
if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A)
oper40 = ieee80211n_check_40mhz_5g(iface, scan_res);
else
oper40 = ieee80211n_check_40mhz_2g4(iface, scan_res);
wpa_scan_results_free(scan_res);
if (!oper40) {
wpa_printf(MSG_INFO, "20/40 MHz operation not permitted on "
"channel pri=%d sec=%d based on overlapping BSSes",
iface->conf->channel,
iface->conf->channel +
iface->conf->secondary_channel * 4);
iface->conf->secondary_channel = 0;
iface->conf->ht_capab &= ~HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET;
}
hostapd_setup_interface_complete(iface, 0);
}
static int ieee80211n_check_40mhz(struct hostapd_iface *iface)
{
struct wpa_driver_scan_params params;
if (!iface->conf->secondary_channel)
return 0; /* HT40 not used */
wpa_printf(MSG_DEBUG, "Scan for neighboring BSSes prior to enabling "
"40 MHz channel");
os_memset(&params, 0, sizeof(params));
/* TODO: scan only the needed frequency */
if (hostapd_driver_scan(iface->bss[0], &params) < 0) {
wpa_printf(MSG_ERROR, "Failed to request a scan of "
"neighboring BSSes");
return -1;
}
iface->scan_cb = ieee80211n_check_scan;
return 1;
}
static int ieee80211n_supported_ht_capab(struct hostapd_iface *iface)
{
u16 hw = iface->current_mode->ht_capab;
u16 conf = iface->conf->ht_capab;
if (!iface->conf->ieee80211n)
return 1;
if ((conf & HT_CAP_INFO_LDPC_CODING_CAP) &&
!(hw & HT_CAP_INFO_LDPC_CODING_CAP)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [LDPC]");
return 0;
}
if ((conf & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
!(hw & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [HT40*]");
return 0;
}
if ((conf & HT_CAP_INFO_SMPS_MASK) != (hw & HT_CAP_INFO_SMPS_MASK) &&
(conf & HT_CAP_INFO_SMPS_MASK) != HT_CAP_INFO_SMPS_DISABLED) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [SMPS-*]");
return 0;
}
if ((conf & HT_CAP_INFO_GREEN_FIELD) &&
!(hw & HT_CAP_INFO_GREEN_FIELD)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [GF]");
return 0;
}
if ((conf & HT_CAP_INFO_SHORT_GI20MHZ) &&
!(hw & HT_CAP_INFO_SHORT_GI20MHZ)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [SHORT-GI-20]");
return 0;
}
if ((conf & HT_CAP_INFO_SHORT_GI40MHZ) &&
!(hw & HT_CAP_INFO_SHORT_GI40MHZ)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [SHORT-GI-40]");
return 0;
}
if ((conf & HT_CAP_INFO_TX_STBC) && !(hw & HT_CAP_INFO_TX_STBC)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [TX-STBC]");
return 0;
}
if ((conf & HT_CAP_INFO_RX_STBC_MASK) >
(hw & HT_CAP_INFO_RX_STBC_MASK)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [RX-STBC*]");
return 0;
}
if ((conf & HT_CAP_INFO_DELAYED_BA) &&
!(hw & HT_CAP_INFO_DELAYED_BA)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [DELAYED-BA]");
return 0;
}
if ((conf & HT_CAP_INFO_MAX_AMSDU_SIZE) &&
!(hw & HT_CAP_INFO_MAX_AMSDU_SIZE)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [MAX-AMSDU-7935]");
return 0;
}
if ((conf & HT_CAP_INFO_DSSS_CCK40MHZ) &&
!(hw & HT_CAP_INFO_DSSS_CCK40MHZ)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [DSSS_CCK-40]");
return 0;
}
if ((conf & HT_CAP_INFO_PSMP_SUPP) && !(hw & HT_CAP_INFO_PSMP_SUPP)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [PSMP]");
return 0;
}
if ((conf & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT) &&
!(hw & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT)) {
wpa_printf(MSG_ERROR, "Driver does not support configured "
"HT capability [LSIG-TXOP-PROT]");
return 0;
}
return 1;
}
#endif /* CONFIG_IEEE80211N */
int hostapd_check_ht_capab(struct hostapd_iface *iface)
{
#ifdef CONFIG_IEEE80211N
int ret;
ret = ieee80211n_check_40mhz(iface);
if (ret)
return ret;
if (!ieee80211n_allowed_ht40_channel_pair(iface))
return -1;
if (!ieee80211n_supported_ht_capab(iface))
return -1;
#endif /* CONFIG_IEEE80211N */
return 0;
}
/**
* hostapd_select_hw_mode - Select the hardware mode
* @iface: Pointer to interface data.
* Returns: 0 on success, -1 on failure
*
* Sets up the hardware mode, channel, rates, and passive scanning
* based on the configuration.
*/
int hostapd_select_hw_mode(struct hostapd_iface *iface)
{
int i, j, ok, ret;
if (iface->num_hw_features < 1)
return -1;
iface->current_mode = NULL;
for (i = 0; i < iface->num_hw_features; i++) {
struct hostapd_hw_modes *mode = &iface->hw_features[i];
if (mode->mode == iface->conf->hw_mode) {
iface->current_mode = mode;
break;
}
}
if (iface->current_mode == NULL) {
wpa_printf(MSG_ERROR, "Hardware does not support configured "
"mode");
hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_WARNING,
"Hardware does not support configured mode "
"(%d)", (int) iface->conf->hw_mode);
return -1;
}
ok = 0;
for (j = 0; j < iface->current_mode->num_channels; j++) {
struct hostapd_channel_data *chan =
&iface->current_mode->channels[j];
if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
(chan->chan == iface->conf->channel)) {
ok = 1;
break;
}
}
if (ok == 0 && iface->conf->channel != 0) {
hostapd_logger(iface->bss[0], NULL,
HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_WARNING,
"Configured channel (%d) not found from the "
"channel list of current mode (%d) %s",
iface->conf->channel,
iface->current_mode->mode,
hostapd_hw_mode_txt(iface->current_mode->mode));
iface->current_mode = NULL;
}
if (iface->current_mode == NULL) {
hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_WARNING,
"Hardware does not support configured channel");
return -1;
}
if (hostapd_prepare_rates(iface->bss[0], iface->current_mode)) {
wpa_printf(MSG_ERROR, "Failed to prepare rates table.");
hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
HOSTAPD_LEVEL_WARNING,
"Failed to prepare rates table.");
return -1;
}
ret = hostapd_passive_scan(iface->bss[0], 0,
iface->conf->passive_scan_mode,
iface->conf->passive_scan_interval,
iface->conf->passive_scan_listen,
NULL, NULL);
if (ret) {
if (ret == -1) {
wpa_printf(MSG_DEBUG, "Passive scanning not "
"supported");
} else {
wpa_printf(MSG_ERROR, "Could not set passive "
"scanning: %s", strerror(ret));
}
ret = 0;
}
return ret;
}
const char * hostapd_hw_mode_txt(int mode)
{
switch (mode) {
case HOSTAPD_MODE_IEEE80211A:
return "IEEE 802.11a";
case HOSTAPD_MODE_IEEE80211B:
return "IEEE 802.11b";
case HOSTAPD_MODE_IEEE80211G:
return "IEEE 802.11g";
default:
return "UNKNOWN";
}
}
int hostapd_hw_get_freq(struct hostapd_data *hapd, int chan)
{
int i;
if (!hapd->iface->current_mode)
return 0;
for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
struct hostapd_channel_data *ch =
&hapd->iface->current_mode->channels[i];
if (ch->chan == chan)
return ch->freq;
}
return 0;
}
int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq)
{
int i;
if (!hapd->iface->current_mode)
return 0;
for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
struct hostapd_channel_data *ch =
&hapd->iface->current_mode->channels[i];
if (ch->freq == freq)
return ch->chan;
}
return 0;
}