hostapd: Add AP DFS support

Add DFS structures/events handlers, CAC handling, and radar detection.
By default, after radar is detected or the channel became unavailable, a
random channel will be chosen.

This patches are based on the original work by Boris Presman and
Victor Goldenshtein. Most of the DFS code is moved to a new dfs.c/dfs.h
files.

Cc: Boris Presman <boris.presman@ti.com>
Cc: Victor Goldenshtein <victorg@ti.com>

Signed-hostap: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-hostap: Janusz Dziedzic <janusz.dziedzic@tieto.com>
This commit is contained in:
Janusz Dziedzic 2013-10-15 20:27:25 +03:00 committed by Jouni Malinen
parent dfe6ce4eeb
commit e76da50529
10 changed files with 423 additions and 10 deletions

View file

@ -782,6 +782,7 @@ OBJS += ../src/ap/wmm.o
OBJS += ../src/ap/ap_list.o
OBJS += ../src/ap/ieee802_11.o
OBJS += ../src/ap/hw_features.o
OBJS += ../src/ap/dfs.o
CFLAGS += -DNEED_AP_MLME
endif
ifdef CONFIG_IEEE80211N

View file

@ -699,3 +699,30 @@ int hostapd_drv_send_action(struct hostapd_data *hapd, unsigned int freq,
hapd->own_addr, hapd->own_addr, data,
len, 0);
}
int hostapd_start_dfs_cac(struct hostapd_data *hapd, int freq, int flags)
{
if (!hapd->driver || !hapd->driver->start_dfs_cac)
return 0;
if (!(flags & HOSTAPD_CHAN_RADAR)) {
wpa_printf(MSG_ERROR, "Can't start DFS_CAC, the channel %u is "
"not DFS channel", hapd->iconf->channel);
return -1;
}
if (!hapd->iface->conf->ieee80211h) {
wpa_printf(MSG_ERROR, "Can't start DFS CAC, DFS functionality "
"is not enabled");
return -1;
}
if (hapd->iface->conf->secondary_channel) {
wpa_printf(MSG_ERROR, "Can't start DFS CAC, DFS functionality "
"on HT40 is not supported");
return -1;
}
return hapd->driver->start_dfs_cac(hapd->drv_priv, freq);
}

View file

@ -101,6 +101,7 @@ int hostapd_sta_assoc(struct hostapd_data *hapd, const u8 *addr,
int reassoc, u16 status, const u8 *ie, size_t len);
int hostapd_add_tspec(struct hostapd_data *hapd, const u8 *addr,
u8 *tspec_ie, size_t tspec_ielen);
int hostapd_start_dfs_cac(struct hostapd_data *hapd, int freq, int flags);
#include "drivers/driver.h"

207
src/ap/dfs.c Normal file
View file

@ -0,0 +1,207 @@
/*
* DFS - Dynamic Frequency Selection
* Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
*
* 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 "hostapd.h"
#include "hw_features.h"
#include "ap_drv_ops.h"
#include "drivers/driver.h"
#include "dfs.h"
static int hostapd_dfs_find_channel(struct hostapd_data *hapd,
struct hostapd_channel_data **ret_chan,
int idx)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan;
int i, channel_idx = 0;
mode = hapd->iface->current_mode;
for (i = 0; i < mode->num_channels; i++) {
chan = &mode->channels[i];
if (chan->flag & HOSTAPD_CHAN_DISABLED)
continue;
if (chan->flag & HOSTAPD_CHAN_RADAR &&
chan->flag & HOSTAPD_CHAN_DFS_UNAVAILABLE)
continue;
if (ret_chan && idx == channel_idx) {
wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
*ret_chan = chan;
return idx;
}
channel_idx++;
}
return channel_idx;
}
struct hostapd_channel_data * hostapd_dfs_get_valid_channel(
struct hostapd_data *hapd)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan = NULL;
int channel_idx, new_channel_idx;
u32 _rand;
wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
if (hapd->iface->current_mode == NULL)
return NULL;
mode = hapd->iface->current_mode;
if (mode->mode != HOSTAPD_MODE_IEEE80211A)
return NULL;
/* get random available channel */
channel_idx = hostapd_dfs_find_channel(hapd, NULL, 0);
if (channel_idx > 0) {
os_get_random((u8 *) &_rand, sizeof(_rand));
new_channel_idx = _rand % channel_idx;
hostapd_dfs_find_channel(hapd, &chan, new_channel_idx);
}
return chan;
}
int ieee802_11_set_dfs_state(struct hostapd_data *hapd, int freq, u32 state)
{
struct hostapd_hw_modes *mode;
struct hostapd_channel_data *chan = NULL;
int i;
mode = hapd->iface->current_mode;
if (mode == NULL)
return 0;
if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
return 0;
}
for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
chan = &hapd->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;
}
/*
* 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_data *hapd)
{
int flags;
struct hostapd_channel_data *channel;
/* Handle DFS channel */
check_dfs_chan_again:
flags = hostapd_hw_get_channel_flag(hapd, hapd->iconf->channel);
if (flags & HOSTAPD_CHAN_RADAR) {
switch (flags & HOSTAPD_CHAN_DFS_MASK) {
case HOSTAPD_CHAN_DFS_USABLE:
wpa_printf(MSG_DEBUG, "DFS start CAC on %d MHz",
hapd->iface->freq);
if (hostapd_start_dfs_cac(hapd,
hapd->iface->freq,
flags)) {
wpa_printf(MSG_DEBUG, "DFS start_dfs_cac() failed");
return -1;
}
/* Continue initialisation after CAC */
return 0;
case HOSTAPD_CHAN_DFS_UNAVAILABLE:
wpa_printf(MSG_DEBUG, "HOSTAPD_CHAN_DFS_UNAVAILABLE, get new chan");
/* find other channel here */
channel = hostapd_dfs_get_valid_channel(hapd);
if (!channel) {
wpa_printf(MSG_ERROR, "could not get valid channel");
return -1;
}
hapd->iconf->channel = channel->chan;
hapd->iface->freq = channel->freq;
goto check_dfs_chan_again;
case HOSTAPD_CHAN_DFS_AVAILABLE:
/* We don't need CAC here */
wpa_printf(MSG_DEBUG, "HOSTAPD_CHAN_DFS_AVAILABLE, skip CAC");
break;
default:
break;
}
}
return 1;
}
int ieee802_11_complete_cac(struct hostapd_data *hapd, int success, int freq)
{
struct hostapd_channel_data *channel;
int err = 1;
if (success) {
/* Complete iface/ap configuration */
ieee802_11_set_dfs_state(hapd, freq,
HOSTAPD_CHAN_DFS_AVAILABLE);
hostapd_setup_interface_complete(hapd->iface, 0);
} else {
/* Switch to new channel */
ieee802_11_set_dfs_state(hapd, freq,
HOSTAPD_CHAN_DFS_UNAVAILABLE);
channel = hostapd_dfs_get_valid_channel(hapd);
if (channel) {
hapd->iconf->channel = channel->chan;
hapd->iface->freq = channel->freq;
err = 0;
} else
wpa_printf(MSG_ERROR, "No valid channel available");
hostapd_setup_interface_complete(hapd->iface, err);
}
return 0;
}
int ieee802_11_start_channel_switch(struct hostapd_data *hapd)
{
struct hostapd_channel_data *channel;
int err = 1;
wpa_printf(MSG_DEBUG, "%s called", __func__);
channel = hostapd_dfs_get_valid_channel(hapd);
if (channel) {
hapd->iconf->channel = channel->chan;
hapd->iface->freq = channel->freq;
err = 0;
}
hapd->driver->stop_ap(hapd->drv_priv);
hostapd_setup_interface_complete(hapd->iface, err);
return 0;
}

18
src/ap/dfs.h Normal file
View file

@ -0,0 +1,18 @@
/*
* DFS - Dynamic Frequency Selection
* Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#ifndef DFS_H
#define DFS_H
struct hostapd_channel_data * hostapd_dfs_get_valid_channel(
struct hostapd_data *hapd);
int ieee802_11_complete_cac(struct hostapd_data *hapd, int success, int freq);
int ieee802_11_set_dfs_state(struct hostapd_data *hapd, int freq, u32 state);
int ieee802_11_start_channel_switch(struct hostapd_data *hapd);
int hostapd_handle_dfs(struct hostapd_data *hapd);
#endif /* DFS_H */

View file

@ -29,6 +29,7 @@
#include "ap_drv_ops.h"
#include "ap_config.h"
#include "hw_features.h"
#include "dfs.h"
int hostapd_notif_assoc(struct hostapd_data *hapd, const u8 *addr,
@ -785,6 +786,61 @@ static void hostapd_event_get_survey(struct hostapd_data *hapd,
}
#ifdef NEED_AP_MLME
static void hostapd_event_dfs_radar_detected(struct hostapd_data *hapd,
struct dfs_event *radar)
{
int res;
wpa_printf(MSG_DEBUG, "DFS radar detected on %d MHz", radar->freq);
if (!hapd->iconf->ieee80211h)
return;
/* mark radar frequency as invalid */
res = ieee802_11_set_dfs_state(hapd, radar->freq,
HOSTAPD_CHAN_DFS_UNAVAILABLE);
/* other frequency, just mark it and return. */
if (hapd->iface->freq != radar->freq)
return;
/* we are working on non-DFS channel - skip event */
if (res == 0)
return;
/* radar detected while operating, switch the channel. */
ieee802_11_start_channel_switch(hapd);
}
static void hostapd_event_dfs_cac_finished(struct hostapd_data *hapd,
struct dfs_event *radar)
{
wpa_printf(MSG_DEBUG, "DFS CAC finished on %d MHz", radar->freq);
ieee802_11_complete_cac(hapd, 1, radar->freq);
}
static void hostapd_event_dfs_cac_aborted(struct hostapd_data *hapd,
struct dfs_event *radar)
{
wpa_printf(MSG_DEBUG, "DFS CAC aborted on %d MHz", radar->freq);
ieee802_11_complete_cac(hapd, 0, radar->freq);
}
static void hostapd_event_dfs_nop_finished(struct hostapd_data *hapd,
struct dfs_event *radar)
{
wpa_printf(MSG_DEBUG, "DFS NOP finished on %d MHz", radar->freq);
ieee802_11_set_dfs_state(hapd, radar->freq, HOSTAPD_CHAN_DFS_USABLE);
}
#endif /* NEED_AP_MLME */
void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
union wpa_event_data *data)
{
@ -929,6 +985,34 @@ void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
case EVENT_SURVEY:
hostapd_event_get_survey(hapd, &data->survey_results);
break;
#ifdef NEED_AP_MLME
case EVENT_DFS_RADAR_DETECTED:
if (!data)
break;
hostapd_event_dfs_radar_detected(hapd, &data->dfs_event);
break;
case EVENT_DFS_CAC_FINISHED:
if (!data)
break;
hostapd_event_dfs_cac_finished(hapd, &data->dfs_event);
break;
case EVENT_DFS_CAC_ABORTED:
if (!data)
break;
hostapd_event_dfs_cac_aborted(hapd, &data->dfs_event);
break;
case EVENT_DFS_NOP_FINISHED:
if (!data)
break;
hostapd_event_dfs_nop_finished(hapd, &data->dfs_event);
break;
case EVENT_CHANNEL_LIST_CHANGED:
/* channel list changed (regulatory?), update channel list */
/* TODO: check this. hostapd_get_hw_features() initializes
* too much stuff. */
/* hostapd_get_hw_features(hapd->iface); */
break;
#endif /* NEED_AP_MLME */
default:
wpa_printf(MSG_DEBUG, "Unknown event %d", event);
break;

View file

@ -32,6 +32,7 @@
#include "ap_config.h"
#include "p2p_hostapd.h"
#include "gas_serv.h"
#include "dfs.h"
static int hostapd_flush_old_stations(struct hostapd_data *hapd, u16 reason);
@ -931,6 +932,9 @@ static int setup_interface(struct hostapd_iface *iface)
"be completed in a callback");
return 0;
}
if (iface->conf->ieee80211h)
wpa_printf(MSG_DEBUG, "DFS support is enabled");
}
return hostapd_setup_interface_complete(iface, 0);
}
@ -950,12 +954,23 @@ int hostapd_setup_interface_complete(struct hostapd_iface *iface, int err)
wpa_printf(MSG_DEBUG, "Completing interface initialization");
if (hapd->iconf->channel) {
#ifdef NEED_AP_MLME
int res;
#endif /* NEED_AP_MLME */
iface->freq = hostapd_hw_get_freq(hapd, hapd->iconf->channel);
wpa_printf(MSG_DEBUG, "Mode: %s Channel: %d "
"Frequency: %d MHz",
hostapd_hw_mode_txt(hapd->iconf->hw_mode),
hapd->iconf->channel, iface->freq);
#ifdef NEED_AP_MLME
/* Check DFS */
res = hostapd_handle_dfs(hapd);
if (res <= 0)
return res;
#endif /* NEED_AP_MLME */
if (hostapd_set_freq(hapd, hapd->iconf->hw_mode, iface->freq,
hapd->iconf->channel,
hapd->iconf->ieee80211n,

View file

@ -45,6 +45,36 @@ void hostapd_free_hw_features(struct hostapd_hw_modes *hw_features,
}
#ifndef CONFIG_NO_STDOUT_DEBUG
static char * dfs_info(struct hostapd_channel_data *chan)
{
static char info[256];
char *state;
switch (chan->flag & HOSTAPD_CHAN_DFS_MASK) {
case HOSTAPD_CHAN_DFS_UNKNOWN:
state = "unknown";
break;
case HOSTAPD_CHAN_DFS_USABLE:
state = "usable";
break;
case HOSTAPD_CHAN_DFS_UNAVAILABLE:
state = "unavailable";
break;
case HOSTAPD_CHAN_DFS_AVAILABLE:
state = "available";
break;
default:
return "";
}
os_snprintf(info, sizeof(info), " (DFS state = %s)", state);
info[sizeof(info) - 1] = '\0';
return info;
}
#endif /* CONFIG_NO_STDOUT_DEBUG */
int hostapd_get_hw_features(struct hostapd_iface *iface)
{
struct hostapd_data *hapd = iface->bss[0];
@ -71,30 +101,40 @@ int hostapd_get_hw_features(struct hostapd_iface *iface)
for (i = 0; i < num_modes; i++) {
struct hostapd_hw_modes *feature = &modes[i];
int dfs_enabled = hapd->iconf->ieee80211h &&
(iface->drv_flags & WPA_DRIVER_FLAGS_RADAR);
/* set flag for channels we can use in current regulatory
* domain */
for (j = 0; j < feature->num_channels; j++) {
int dfs = 0;
/*
* 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.
* IBSS operation or active scanning.
* Use radar channels only if the driver supports DFS.
*/
if (feature->channels[j].flag &
(HOSTAPD_CHAN_NO_IBSS |
HOSTAPD_CHAN_PASSIVE_SCAN |
HOSTAPD_CHAN_RADAR))
if ((feature->channels[j].flag &
HOSTAPD_CHAN_RADAR) && dfs_enabled) {
dfs = 1;
} else 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",
"chan=%d freq=%d MHz max_tx_power=%d dBm%s",
feature->mode,
feature->channels[j].chan,
feature->channels[j].freq,
feature->channels[j].max_tx_power);
feature->channels[j].max_tx_power,
dfs ? dfs_info(&feature->channels[j]) : "");
}
}
@ -849,3 +889,21 @@ int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq)
return 0;
}
int hostapd_hw_get_channel_flag(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->flag;
}
return 0;
}

View file

@ -28,6 +28,7 @@ int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq);
int hostapd_check_ht_capab(struct hostapd_iface *iface);
int hostapd_prepare_rates(struct hostapd_iface *iface,
struct hostapd_hw_modes *mode);
int hostapd_hw_get_channel_flag(struct hostapd_data *hapd, int chan);
#else /* NEED_AP_MLME */
static inline void
hostapd_free_hw_features(struct hostapd_hw_modes *hw_features,

View file

@ -772,6 +772,7 @@ OBJS += ../src/ap/wmm.o
OBJS += ../src/ap/ap_list.o
OBJS += ../src/ap/ieee802_11.o
OBJS += ../src/ap/hw_features.o
OBJS += ../src/ap/dfs.o
CFLAGS += -DNEED_AP_MLME
endif
ifdef CONFIG_WPS