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hostapd: Add AP DFS support

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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
Show stats Download patch file Download diff file Expand all files Collapse all files

1
hostapd/Makefile
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

27
src/ap/ap_drv_ops.c
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);
}

1
src/ap/ap_drv_ops.h
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 */

84
src/ap/drv_callbacks.c
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;

15
src/ap/hostapd.c
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,

78
src/ap/hw_features.c
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;
}

1
src/ap/hw_features.h
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,

1
wpa_supplicant/Makefile
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