/*
* DFS - Dynamic Frequency Selection
* Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
* Copyright (c) 2013-2015, Qualcomm Atheros, Inc.
*
* 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 "common/ieee802_11_defs.h"
#include "common/hw_features_common.h"
#include "common/wpa_ctrl.h"
#include "hostapd.h"
#include "ap_drv_ops.h"
#include "drivers/driver.h"
#include "dfs.h"
static int dfs_get_used_n_chans(struct hostapd_iface *iface, int *seg1)
{
int n_chans = 1;
*seg1 = 0;
if (iface->conf->ieee80211n && iface->conf->secondary_channel)
n_chans = 2;
if (iface->conf->ieee80211ac) {
switch (iface->conf->vht_oper_chwidth) {
case VHT_CHANWIDTH_USE_HT:
break;
case VHT_CHANWIDTH_80MHZ:
n_chans = 4;
break;
case VHT_CHANWIDTH_160MHZ:
n_chans = 8;
break;
case VHT_CHANWIDTH_80P80MHZ:
n_chans = 4;
*seg1 = 4;
break;
default:
break;
}
}
return n_chans;
}
static int dfs_channel_available(struct hostapd_channel_data *chan,
int skip_radar)
{
/*
* When radar detection happens, CSA is performed. However, there's no
* time for CAC, so radar channels must be skipped when finding a new
* channel for CSA, unless they are available for immediate use.
*/
if (skip_radar && (chan->flag & HOSTAPD_CHAN_RADAR) &&
((chan->flag & HOSTAPD_CHAN_DFS_MASK) !=
HOSTAPD_CHAN_DFS_AVAILABLE))
return 0;
if (chan->flag & HOSTAPD_CHAN_DISABLED)
return 0;
if ((chan->flag & HOSTAPD_CHAN_RADAR) &&
((chan->flag & HOSTAPD_CHAN_DFS_MASK) ==
HOSTAPD_CHAN_DFS_UNAVAILABLE))
return 0;
return 1;
}
static int dfs_is_chan_allowed(struct hostapd_channel_data *chan, int n_chans)
{
/*
* The tables contain first valid channel number based on channel width.
* We will also choose this first channel as the control one.
*/
int allowed_40[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
184, 192 };
/*
* VHT80, valid channels based on center frequency:
* 42, 58, 106, 122, 138, 155
*/
int allowed_80[] = { 36, 52, 100, 116, 132, 149 };
/*
* VHT160 valid channels based on center frequency:
* 50, 114
*/
int allowed_160[] = { 36, 100 };
int *allowed = allowed_40;
unsigned int i, allowed_no = 0;
switch (n_chans) {
case 2:
allowed = allowed_40;
allowed_no = ARRAY_SIZE(allowed_40);
break;
case 4:
allowed = allowed_80;
allowed_no = ARRAY_SIZE(allowed_80);
break;
case 8:
allowed = allowed_160;
allowed_no = ARRAY_SIZE(allowed_160);
break;
default:
wpa_printf(MSG_DEBUG, "Unknown width for %d channels", n_chans);
break;
}
for (i = 0; i < allowed_no; i++) {
if (chan->chan == allowed[i])
return 1;
}
return 0;
}
static struct hostapd_channel_data *
dfs_get_chan_data(struct hostapd_hw_modes *mode, int freq, int first_chan_idx)
{
int i;
for (i = first_chan_idx; i < mode->num_channels; i++) {
if (mode->channels[i].freq == freq)
return &mode->channels[i];
}
return NULL;
}
static int dfs_chan_range_available(struct hostapd_hw_modes *mode,
int first_chan_idx, int num_chans,
int skip_radar)
{
struct hostapd_channel_data *first_chan, *chan;
int i;
if (first_chan_idx + num_chans > mode->num_channels)
return 0;
first_chan = &mode->channels[first_chan_idx];
for (i = 0; i < num_chans; i++) {
chan = dfs_get_chan_data(mode, first_chan->freq + i * 20,
first_chan_idx);
if (!chan)
return 0;
if (!dfs_channel_available(chan, skip_radar))
return 0;
}
return 1;
}
static int is_in_chanlist(struct hostapd_iface *iface,
struct hostapd_channel_data *chan)
{
if (!iface->conf->acs_ch_list.num)
return 1;
return freq_range_list_includes(&iface->conf->acs_ch_list, chan->chan);
}
/*
* The function assumes HT40+ operation.
* Make sure to adjust the following variables after calling this:
* - hapd->secondary_channel
* - hapd->vht_oper_centr_freq_seg0_idx
* - hapd->vht_oper_centr_freq_seg1_idx
*/
static int dfs_find_channel(struct hostapd_iface *iface,
struct hostapd_channel_data **ret_chan,
int idx, int skip_radar)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan;
int i, channel_idx = 0, n_chans, n_chans1;
mode = iface->current_mode;
n_chans = dfs_get_used_n_chans(iface, &n_chans1);
wpa_printf(MSG_DEBUG, "DFS new chan checking %d channels", n_chans);
for (i = 0; i < mode->num_channels; i++) {
chan = &mode->channels[i];
/* Skip HT40/VHT incompatible channels */
if (iface->conf->ieee80211n &&
iface->conf->secondary_channel &&
!dfs_is_chan_allowed(chan, n_chans))
continue;
/* Skip incompatible chandefs */
if (!dfs_chan_range_available(mode, i, n_chans, skip_radar))
continue;
if (!is_in_chanlist(iface, chan))
continue;
if (ret_chan && idx == channel_idx) {
wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
*ret_chan = chan;
return idx;
}
wpa_printf(MSG_DEBUG, "Adding channel: %d", chan->chan);
channel_idx++;
}
return channel_idx;
}
static void dfs_adjust_vht_center_freq(struct hostapd_iface *iface,
struct hostapd_channel_data *chan,
int secondary_channel,
u8 *vht_oper_centr_freq_seg0_idx,
u8 *vht_oper_centr_freq_seg1_idx)
{
if (!iface->conf->ieee80211ac)
return;
if (!chan)
return;
*vht_oper_centr_freq_seg1_idx = 0;
switch (iface->conf->vht_oper_chwidth) {
case VHT_CHANWIDTH_USE_HT:
if (secondary_channel == 1)
*vht_oper_centr_freq_seg0_idx = chan->chan + 2;
else if (secondary_channel == -1)
*vht_oper_centr_freq_seg0_idx = chan->chan - 2;
else
*vht_oper_centr_freq_seg0_idx = chan->chan;
break;
case VHT_CHANWIDTH_80MHZ:
*vht_oper_centr_freq_seg0_idx = chan->chan + 6;
break;
case VHT_CHANWIDTH_160MHZ:
*vht_oper_centr_freq_seg0_idx = chan->chan + 14;
break;
default:
wpa_printf(MSG_INFO, "DFS only VHT20/40/80/160 is supported now");
*vht_oper_centr_freq_seg0_idx = 0;
break;
}
wpa_printf(MSG_DEBUG, "DFS adjusting VHT center frequency: %d, %d",
*vht_oper_centr_freq_seg0_idx,
*vht_oper_centr_freq_seg1_idx);
}
/* Return start channel idx we will use for mode->channels[idx] */
static int dfs_get_start_chan_idx(struct hostapd_iface *iface, int *seg1_start)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan;
int channel_no = iface->conf->channel;
int res = -1, i;
int chan_seg1 = -1;
*seg1_start = -1;
/* HT40- */
if (iface->conf->ieee80211n && iface->conf->secondary_channel == -1)
channel_no -= 4;
/* VHT */
if (iface->conf->ieee80211ac) {
switch (iface->conf->vht_oper_chwidth) {
case VHT_CHANWIDTH_USE_HT:
break;
case VHT_CHANWIDTH_80MHZ:
channel_no =
iface->conf->vht_oper_centr_freq_seg0_idx - 6;
break;
case VHT_CHANWIDTH_160MHZ:
channel_no =
iface->conf->vht_oper_centr_freq_seg0_idx - 14;
break;
case VHT_CHANWIDTH_80P80MHZ:
channel_no =
iface->conf->vht_oper_centr_freq_seg0_idx - 6;
chan_seg1 =
iface->conf->vht_oper_centr_freq_seg1_idx - 6;
break;
default:
wpa_printf(MSG_INFO,
"DFS only VHT20/40/80/160/80+80 is supported now");
channel_no = -1;
break;
}
}
/* Get idx */
mode = iface->current_mode;
for (i = 0; i < mode->num_channels; i++) {
chan = &mode->channels[i];
if (chan->chan == channel_no) {
res = i;
break;
}
}
if (res != -1 && chan_seg1 > -1) {
int found = 0;
/* Get idx for seg1 */
mode = iface->current_mode;
for (i = 0; i < mode->num_channels; i++) {
chan = &mode->channels[i];
if (chan->chan == chan_seg1) {
*seg1_start = i;
found = 1;
break;
}
}
if (!found)
res = -1;
}
if (res == -1) {
wpa_printf(MSG_DEBUG,
"DFS chan_idx seems wrong; num-ch: %d ch-no: %d conf-ch-no: %d 11n: %d sec-ch: %d vht-oper-width: %d",
mode->num_channels, channel_no, iface->conf->channel,
iface->conf->ieee80211n,
iface->conf->secondary_channel,
iface->conf->vht_oper_chwidth);
for (i = 0; i < mode->num_channels; i++) {
wpa_printf(MSG_DEBUG, "Available channel: %d",
mode->channels[i].chan);
}
}
return res;
}
/* At least one channel have radar flag */
static int dfs_check_chans_radar(struct hostapd_iface *iface,
int start_chan_idx, int n_chans)
{
struct hostapd_channel_data *channel;
struct hostapd_hw_modes *mode;
int i, res = 0;
mode = iface->current_mode;
for (i = 0; i < n_chans; i++) {
channel = &mode->channels[start_chan_idx + i];
if (channel->flag & HOSTAPD_CHAN_RADAR)
res++;
}
return res;
}
/* All channels available */
static int dfs_check_chans_available(struct hostapd_iface *iface,
int start_chan_idx, int n_chans)
{
struct hostapd_channel_data *channel;
struct hostapd_hw_modes *mode;
int i;
mode = iface->current_mode;
for (i = 0; i < n_chans; i++) {
channel = &mode->channels[start_chan_idx + i];
if (channel->flag & HOSTAPD_CHAN_DISABLED)
break;
if (!(channel->flag & HOSTAPD_CHAN_RADAR))
continue;
if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) !=
HOSTAPD_CHAN_DFS_AVAILABLE)
break;
}
return i == n_chans;
}
/* At least one channel unavailable */
static int dfs_check_chans_unavailable(struct hostapd_iface *iface,
int start_chan_idx,
int n_chans)
{
struct hostapd_channel_data *channel;
struct hostapd_hw_modes *mode;
int i, res = 0;
mode = iface->current_mode;
for (i = 0; i < n_chans; i++) {
channel = &mode->channels[start_chan_idx + i];
if (channel->flag & HOSTAPD_CHAN_DISABLED)
res++;
if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) ==
HOSTAPD_CHAN_DFS_UNAVAILABLE)
res++;
}
return res;
}
static struct hostapd_channel_data *
dfs_get_valid_channel(struct hostapd_iface *iface,
int *secondary_channel,
u8 *vht_oper_centr_freq_seg0_idx,
u8 *vht_oper_centr_freq_seg1_idx,
int skip_radar)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan = NULL;
int num_available_chandefs;
int chan_idx;
u32 _rand;
wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
*secondary_channel = 0;
*vht_oper_centr_freq_seg0_idx = 0;
*vht_oper_centr_freq_seg1_idx = 0;
if (iface->current_mode == NULL)
return NULL;
mode = iface->current_mode;
if (mode->mode != HOSTAPD_MODE_IEEE80211A)
return NULL;
/* Get the count first */
num_available_chandefs = dfs_find_channel(iface, NULL, 0, skip_radar);
if (num_available_chandefs == 0)
return NULL;
if (os_get_random((u8 *) &_rand, sizeof(_rand)) < 0)
return NULL;
chan_idx = _rand % num_available_chandefs;
dfs_find_channel(iface, &chan, chan_idx, skip_radar);
/* dfs_find_channel() calculations assume HT40+ */
if (iface->conf->secondary_channel)
*secondary_channel = 1;
else
*secondary_channel = 0;
dfs_adjust_vht_center_freq(iface, chan,
*secondary_channel,
vht_oper_centr_freq_seg0_idx,
vht_oper_centr_freq_seg1_idx);
return chan;
}
static int set_dfs_state_freq(struct hostapd_iface *iface, int freq, u32 state)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan = NULL;
int i;
mode = iface->current_mode;
if (mode == NULL)
return 0;
wpa_printf(MSG_DEBUG, "set_dfs_state 0x%X for %d MHz", state, freq);
for (i = 0; i < iface->current_mode->num_channels; i++) {
chan = &iface->current_mode->channels[i];
if (chan->freq == freq) {
if (chan->flag & HOSTAPD_CHAN_RADAR) {
chan->flag &= ~HOSTAPD_CHAN_DFS_MASK;
chan->flag |= state;
return 1; /* Channel found */
}
}
}
wpa_printf(MSG_WARNING, "Can't set DFS state for freq %d MHz", freq);
return 0;
}
static int set_dfs_state(struct hostapd_iface *iface, int freq, int ht_enabled,
int chan_offset, int chan_width, int cf1,
int cf2, u32 state)
{
int n_chans = 1, i;
struct hostapd_hw_modes *mode;
int frequency = freq;
int ret = 0;
mode = iface->current_mode;
if (mode == NULL)
return 0;
if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
return 0;
}
/* Seems cf1 and chan_width is enough here */
switch (chan_width) {
case CHAN_WIDTH_20_NOHT:
case CHAN_WIDTH_20:
n_chans = 1;
if (frequency == 0)
frequency = cf1;
break;
case CHAN_WIDTH_40:
n_chans = 2;
frequency = cf1 - 10;
break;
case CHAN_WIDTH_80:
n_chans = 4;
frequency = cf1 - 30;
break;
case CHAN_WIDTH_160:
n_chans = 8;
frequency = cf1 - 70;
break;
default:
wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
chan_width);
break;
}
wpa_printf(MSG_DEBUG, "DFS freq: %dMHz, n_chans: %d", frequency,
n_chans);
for (i = 0; i < n_chans; i++) {
ret += set_dfs_state_freq(iface, frequency, state);
frequency = frequency + 20;
}
return ret;
}
static int dfs_are_channels_overlapped(struct hostapd_iface *iface, int freq,
int chan_width, int cf1, int cf2)
{
int start_chan_idx, start_chan_idx1;
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan;
int n_chans, n_chans1, i, j, frequency = freq, radar_n_chans = 1;
u8 radar_chan;
int res = 0;
/* Our configuration */
mode = iface->current_mode;
start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
n_chans = dfs_get_used_n_chans(iface, &n_chans1);
/* Check we are on DFS channel(s) */
if (!dfs_check_chans_radar(iface, start_chan_idx, n_chans))
return 0;
/* Reported via radar event */
switch (chan_width) {
case CHAN_WIDTH_20_NOHT:
case CHAN_WIDTH_20:
radar_n_chans = 1;
if (frequency == 0)
frequency = cf1;
break;
case CHAN_WIDTH_40:
radar_n_chans = 2;
frequency = cf1 - 10;
break;
case CHAN_WIDTH_80:
radar_n_chans = 4;
frequency = cf1 - 30;
break;
case CHAN_WIDTH_160:
radar_n_chans = 8;
frequency = cf1 - 70;
break;
default:
wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
chan_width);
break;
}
ieee80211_freq_to_chan(frequency, &radar_chan);
for (i = 0; i < n_chans; i++) {
chan = &mode->channels[start_chan_idx + i];
if (!(chan->flag & HOSTAPD_CHAN_RADAR))
continue;
for (j = 0; j < radar_n_chans; j++) {
wpa_printf(MSG_DEBUG, "checking our: %d, radar: %d",
chan->chan, radar_chan + j * 4);
if (chan->chan == radar_chan + j * 4)
res++;
}
}
wpa_printf(MSG_DEBUG, "overlapped: %d", res);
return res;
}
static unsigned int dfs_get_cac_time(struct hostapd_iface *iface,
int start_chan_idx, int n_chans)
{
struct hostapd_channel_data *channel;
struct hostapd_hw_modes *mode;
int i;
unsigned int cac_time_ms = 0;
mode = iface->current_mode;
for (i = 0; i < n_chans; i++) {
channel = &mode->channels[start_chan_idx + i];
if (!(channel->flag & HOSTAPD_CHAN_RADAR))
continue;
if (channel->dfs_cac_ms > cac_time_ms)
cac_time_ms = channel->dfs_cac_ms;
}
return cac_time_ms;
}
/*
* Main DFS handler
* 1 - continue channel/ap setup
* 0 - channel/ap setup will be continued after CAC
* -1 - hit critical error
*/
int hostapd_handle_dfs(struct hostapd_iface *iface)
{
struct hostapd_channel_data *channel;
int res, n_chans, n_chans1, start_chan_idx, start_chan_idx1;
int skip_radar = 0;
if (!iface->current_mode) {
/*
* This can happen with drivers that do not provide mode
* information and as such, cannot really use hostapd for DFS.
*/
wpa_printf(MSG_DEBUG,
"DFS: No current_mode information - assume no need to perform DFS operations by hostapd");
return 1;
}
iface->cac_started = 0;
do {
/* Get start (first) channel for current configuration */
start_chan_idx = dfs_get_start_chan_idx(iface,
&start_chan_idx1);
if (start_chan_idx == -1)
return -1;
/* Get number of used channels, depend on width */
n_chans = dfs_get_used_n_chans(iface, &n_chans1);
/* Setup CAC time */
iface->dfs_cac_ms = dfs_get_cac_time(iface, start_chan_idx,
n_chans);
/* Check if any of configured channels require DFS */
res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
wpa_printf(MSG_DEBUG,
"DFS %d channels required radar detection",
res);
if (!res)
return 1;
/* Check if all channels are DFS available */
res = dfs_check_chans_available(iface, start_chan_idx, n_chans);
wpa_printf(MSG_DEBUG,
"DFS all channels available, (SKIP CAC): %s",
res ? "yes" : "no");
if (res)
return 1;
/* Check if any of configured channels is unavailable */
res = dfs_check_chans_unavailable(iface, start_chan_idx,
n_chans);
wpa_printf(MSG_DEBUG, "DFS %d chans unavailable - choose other channel: %s",
res, res ? "yes": "no");
if (res) {
int sec = 0;
u8 cf1 = 0, cf2 = 0;
channel = dfs_get_valid_channel(iface, &sec, &cf1, &cf2,
skip_radar);
if (!channel) {
wpa_printf(MSG_ERROR, "could not get valid channel");
hostapd_set_state(iface, HAPD_IFACE_DFS);
return 0;
}
iface->freq = channel->freq;
iface->conf->channel = channel->chan;
iface->conf->secondary_channel = sec;
iface->conf->vht_oper_centr_freq_seg0_idx = cf1;
iface->conf->vht_oper_centr_freq_seg1_idx = cf2;
}
} while (res);
/* Finally start CAC */
hostapd_set_state(iface, HAPD_IFACE_DFS);
wpa_printf(MSG_DEBUG, "DFS start CAC on %d MHz", iface->freq);
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
"freq=%d chan=%d sec_chan=%d, width=%d, seg0=%d, seg1=%d, cac_time=%ds",
iface->freq,
iface->conf->channel, iface->conf->secondary_channel,
iface->conf->vht_oper_chwidth,
iface->conf->vht_oper_centr_freq_seg0_idx,
iface->conf->vht_oper_centr_freq_seg1_idx,
iface->dfs_cac_ms / 1000);
res = hostapd_start_dfs_cac(iface, iface->conf->hw_mode,
iface->freq,
iface->conf->channel,
iface->conf->ieee80211n,
iface->conf->ieee80211ac,
iface->conf->secondary_channel,
iface->conf->vht_oper_chwidth,
iface->conf->vht_oper_centr_freq_seg0_idx,
iface->conf->vht_oper_centr_freq_seg1_idx);
if (res) {
wpa_printf(MSG_ERROR, "DFS start_dfs_cac() failed, %d", res);
return -1;
}
return 0;
}
int hostapd_dfs_complete_cac(struct hostapd_iface *iface, int success, int freq,
int ht_enabled, int chan_offset, int chan_width,
int cf1, int cf2)
{
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_COMPLETED
"success=%d freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
success, freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
if (success) {
/* Complete iface/ap configuration */
if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD) {
/* Complete AP configuration for the first bring up. */
if (iface->state != HAPD_IFACE_ENABLED)
hostapd_setup_interface_complete(iface, 0);
else
iface->cac_started = 0;
} else {
set_dfs_state(iface, freq, ht_enabled, chan_offset,
chan_width, cf1, cf2,
HOSTAPD_CHAN_DFS_AVAILABLE);
iface->cac_started = 0;
hostapd_setup_interface_complete(iface, 0);
}
}
return 0;
}
static int hostapd_dfs_start_channel_switch_cac(struct hostapd_iface *iface)
{
struct hostapd_channel_data *channel;
int secondary_channel;
u8 vht_oper_centr_freq_seg0_idx = 0;
u8 vht_oper_centr_freq_seg1_idx = 0;
int skip_radar = 0;
int err = 1;
/* Radar detected during active CAC */
iface->cac_started = 0;
channel = dfs_get_valid_channel(iface, &secondary_channel,
&vht_oper_centr_freq_seg0_idx,
&vht_oper_centr_freq_seg1_idx,
skip_radar);
if (!channel) {
wpa_printf(MSG_ERROR, "No valid channel available");
return err;
}
wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
channel->chan);
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
"freq=%d chan=%d sec_chan=%d", channel->freq,
channel->chan, secondary_channel);
iface->freq = channel->freq;
iface->conf->channel = channel->chan;
iface->conf->secondary_channel = secondary_channel;
iface->conf->vht_oper_centr_freq_seg0_idx =
vht_oper_centr_freq_seg0_idx;
iface->conf->vht_oper_centr_freq_seg1_idx =
vht_oper_centr_freq_seg1_idx;
err = 0;
hostapd_setup_interface_complete(iface, err);
return err;
}
static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
{
struct hostapd_channel_data *channel;
int secondary_channel;
u8 vht_oper_centr_freq_seg0_idx;
u8 vht_oper_centr_freq_seg1_idx;
int skip_radar = 1;
struct csa_settings csa_settings;
unsigned int i;
int err = 1;
wpa_printf(MSG_DEBUG, "%s called (CAC active: %s, CSA active: %s)",
__func__, iface->cac_started ? "yes" : "no",
hostapd_csa_in_progress(iface) ? "yes" : "no");
/* Check if CSA in progress */
if (hostapd_csa_in_progress(iface))
return 0;
/* Check if active CAC */
if (iface->cac_started)
return hostapd_dfs_start_channel_switch_cac(iface);
/* Perform channel switch/CSA */
channel = dfs_get_valid_channel(iface, &secondary_channel,
&vht_oper_centr_freq_seg0_idx,
&vht_oper_centr_freq_seg1_idx,
skip_radar);
if (!channel) {
/*
* If there is no channel to switch immediately to, check if
* there is another channel where we can switch even if it
* requires to perform a CAC first.
*/
skip_radar = 0;
channel = dfs_get_valid_channel(iface, &secondary_channel,
&vht_oper_centr_freq_seg0_idx,
&vht_oper_centr_freq_seg1_idx,
skip_radar);
if (!channel) {
wpa_printf(MSG_INFO,
"%s: no DFS channels left, waiting for NOP to finish",
__func__);
return err;
}
iface->freq = channel->freq;
iface->conf->channel = channel->chan;
iface->conf->secondary_channel = secondary_channel;
iface->conf->vht_oper_centr_freq_seg0_idx =
vht_oper_centr_freq_seg0_idx;
iface->conf->vht_oper_centr_freq_seg1_idx =
vht_oper_centr_freq_seg1_idx;
hostapd_disable_iface(iface);
hostapd_enable_iface(iface);
return 0;
}
wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
channel->chan);
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
"freq=%d chan=%d sec_chan=%d", channel->freq,
channel->chan, secondary_channel);
/* Setup CSA request */
os_memset(&csa_settings, 0, sizeof(csa_settings));
csa_settings.cs_count = 5;
csa_settings.block_tx = 1;
err = hostapd_set_freq_params(&csa_settings.freq_params,
iface->conf->hw_mode,
channel->freq,
channel->chan,
iface->conf->ieee80211n,
iface->conf->ieee80211ac,
secondary_channel,
iface->conf->vht_oper_chwidth,
vht_oper_centr_freq_seg0_idx,
vht_oper_centr_freq_seg1_idx,
iface->current_mode->vht_capab);
if (err) {
wpa_printf(MSG_ERROR, "DFS failed to calculate CSA freq params");
hostapd_disable_iface(iface);
return err;
}
for (i = 0; i < iface->num_bss; i++) {
err = hostapd_switch_channel(iface->bss[i], &csa_settings);
if (err)
break;
}
if (err) {
wpa_printf(MSG_WARNING, "DFS failed to schedule CSA (%d) - trying fallback",
err);
iface->freq = channel->freq;
iface->conf->channel = channel->chan;
iface->conf->secondary_channel = secondary_channel;
iface->conf->vht_oper_centr_freq_seg0_idx =
vht_oper_centr_freq_seg0_idx;
iface->conf->vht_oper_centr_freq_seg1_idx =
vht_oper_centr_freq_seg1_idx;
hostapd_disable_iface(iface);
hostapd_enable_iface(iface);
return 0;
}
/* Channel configuration will be updated once CSA completes and
* ch_switch_notify event is received */
wpa_printf(MSG_DEBUG, "DFS waiting channel switch event");
return 0;
}
int hostapd_dfs_radar_detected(struct hostapd_iface *iface, int freq,
int ht_enabled, int chan_offset, int chan_width,
int cf1, int cf2)
{
int res;
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_RADAR_DETECTED
"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
/* Proceed only if DFS is not offloaded to the driver */
if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
return 0;
if (!iface->conf->ieee80211h)
return 0;
/* mark radar frequency as invalid */
set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
cf1, cf2, HOSTAPD_CHAN_DFS_UNAVAILABLE);
/* Skip if reported radar event not overlapped our channels */
res = dfs_are_channels_overlapped(iface, freq, chan_width, cf1, cf2);
if (!res)
return 0;
/* radar detected while operating, switch the channel. */
res = hostapd_dfs_start_channel_switch(iface);
return res;
}
int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
int ht_enabled, int chan_offset, int chan_width,
int cf1, int cf2)
{
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NOP_FINISHED
"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
/* Proceed only if DFS is not offloaded to the driver */
if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
return 0;
/* TODO add correct implementation here */
set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
/* Handle cases where all channels were initially unavailable */
if (iface->state == HAPD_IFACE_DFS && !iface->cac_started)
hostapd_handle_dfs(iface);
return 0;
}
int hostapd_is_dfs_required(struct hostapd_iface *iface)
{
int n_chans, n_chans1, start_chan_idx, start_chan_idx1, res;
if (!iface->conf->ieee80211h || !iface->current_mode ||
iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
return 0;
/* Get start (first) channel for current configuration */
start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
if (start_chan_idx == -1)
return -1;
/* Get number of used channels, depend on width */
n_chans = dfs_get_used_n_chans(iface, &n_chans1);
/* Check if any of configured channels require DFS */
res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
if (res)
return res;
if (start_chan_idx1 >= 0 && n_chans1 > 0)
res = dfs_check_chans_radar(iface, start_chan_idx1, n_chans1);
return res;
}
int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
int ht_enabled, int chan_offset, int chan_width,
int cf1, int cf2)
{
wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
"freq=%d chan=%d chan_offset=%d width=%d seg0=%d "
"seg1=%d cac_time=%ds",
freq, (freq - 5000) / 5, chan_offset, chan_width, cf1, cf2, 60);
iface->cac_started = 1;
return 0;
}
/*
* Main DFS handler for offloaded case.
* 2 - continue channel/AP setup for non-DFS channel
* 1 - continue channel/AP setup for DFS channel
* 0 - channel/AP setup will be continued after CAC
* -1 - hit critical error
*/
int hostapd_handle_dfs_offload(struct hostapd_iface *iface)
{
wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
__func__, iface->cac_started);
/*
* If DFS has already been started, then we are being called from a
* callback to continue AP/channel setup. Reset the CAC start flag and
* return.
*/
if (iface->cac_started) {
wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
__func__, iface->cac_started);
iface->cac_started = 0;
return 1;
}
if (ieee80211_is_dfs(iface->freq)) {
wpa_printf(MSG_DEBUG, "%s: freq %d MHz requires DFS",
__func__, iface->freq);
return 0;
}
wpa_printf(MSG_DEBUG,
"%s: freq %d MHz does not require DFS. Continue channel/AP setup",
__func__, iface->freq);
return 2;
}