Move to the advertised channel on reception of
a CSA element. This is needed for 802.11h compliance.
Signed-off-by: Sujith <[email protected]>
---
v2
--
* Add a new variable to hold the CSA channel
* Use msecs_to_jiffies for calculating expiration time
* Add a check to drop beacons in case of a frequency mismatch
net/mac80211/ieee80211_i.h | 11 ++++++-
net/mac80211/iface.c | 2 +
net/mac80211/mlme.c | 13 +++++++
net/mac80211/rx.c | 17 ++++++++++
net/mac80211/spectmgmt.c | 77 ++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 119 insertions(+), 1 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 117718b..d2a007a 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -259,6 +259,7 @@ struct mesh_preq_queue {
#define IEEE80211_STA_AUTO_CHANNEL_SEL BIT(12)
#define IEEE80211_STA_PRIVACY_INVOKED BIT(13)
#define IEEE80211_STA_TKIP_WEP_USED BIT(14)
+#define IEEE80211_STA_CSA_RECEIVED BIT(15)
/* flags for MLME request */
#define IEEE80211_STA_REQ_SCAN 0
#define IEEE80211_STA_REQ_DIRECT_PROBE 1
@@ -283,7 +284,9 @@ enum ieee80211_sta_mlme_state {
struct ieee80211_if_sta {
struct timer_list timer;
+ struct timer_list chswitch_timer;
struct work_struct work;
+ struct work_struct chswitch_work;
u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
u8 ssid[IEEE80211_MAX_SSID_LEN];
enum ieee80211_sta_mlme_state state;
@@ -542,6 +545,7 @@ enum {
enum queue_stop_reason {
IEEE80211_QUEUE_STOP_REASON_DRIVER,
IEEE80211_QUEUE_STOP_REASON_PS,
+ IEEE80211_QUEUE_STOP_REASON_CSA
};
/* maximum number of hardware queues we support. */
@@ -631,7 +635,7 @@ struct ieee80211_local {
unsigned long last_scan_completed;
struct delayed_work scan_work;
struct ieee80211_sub_if_data *scan_sdata;
- struct ieee80211_channel *oper_channel, *scan_channel;
+ struct ieee80211_channel *oper_channel, *scan_channel, *csa_channel;
enum nl80211_channel_type oper_channel_type;
u8 scan_ssid[IEEE80211_MAX_SSID_LEN];
size_t scan_ssid_len;
@@ -964,6 +968,11 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len);
+void ieee80211_chswitch_timer(unsigned long data);
+void ieee80211_chswitch_work(struct work_struct *work);
+void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_channel_sw_ie *sw_elem,
+ struct ieee80211_bss *bss);
/* utility functions/constants */
extern void *mac80211_wiphy_privid; /* for wiphy privid */
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 2c7a87d..f927641 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -443,6 +443,7 @@ static int ieee80211_stop(struct net_device *dev)
WLAN_REASON_DEAUTH_LEAVING);
memset(sdata->u.sta.bssid, 0, ETH_ALEN);
+ del_timer_sync(&sdata->u.sta.chswitch_timer);
del_timer_sync(&sdata->u.sta.timer);
/*
* If the timer fired while we waited for it, it will have
@@ -452,6 +453,7 @@ static int ieee80211_stop(struct net_device *dev)
* it no longer is.
*/
cancel_work_sync(&sdata->u.sta.work);
+ cancel_work_sync(&sdata->u.sta.chswitch_work);
/*
* When we get here, the interface is marked down.
* Call synchronize_rcu() to wait for the RX path
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e317c6d..4d25cf9 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1645,6 +1645,13 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
if (!bss)
return;
+ if (elems->ch_switch_elem && (elems->ch_switch_elem_len == 3) &&
+ (memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0)) {
+ struct ieee80211_channel_sw_ie *sw_elem =
+ (struct ieee80211_channel_sw_ie *)elems->ch_switch_elem;
+ ieee80211_process_chanswitch(sdata, sw_elem, bss);
+ }
+
/* was just updated in ieee80211_bss_info_update */
beacon_timestamp = bss->timestamp;
@@ -1781,6 +1788,9 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
memcmp(ifsta->bssid, mgmt->bssid, ETH_ALEN) != 0)
return;
+ if (rx_status->freq != local->hw.conf.channel->center_freq)
+ return;
+
ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
elems.wmm_param_len);
@@ -2447,8 +2457,11 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
ifsta = &sdata->u.sta;
INIT_WORK(&ifsta->work, ieee80211_sta_work);
+ INIT_WORK(&ifsta->chswitch_work, ieee80211_chswitch_work);
setup_timer(&ifsta->timer, ieee80211_sta_timer,
(unsigned long) sdata);
+ setup_timer(&ifsta->chswitch_timer, ieee80211_chswitch_timer,
+ (unsigned long) sdata);
skb_queue_head_init(&ifsta->skb_queue);
ifsta->capab = WLAN_CAPABILITY_ESS;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 384cb3b..c8daf8a 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1564,7 +1564,9 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
{
struct ieee80211_local *local = rx->local;
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
+ struct ieee80211_if_sta *ifsta = &sdata->u.sta;
struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+ struct ieee80211_bss *bss;
int len = rx->skb->len;
if (!ieee80211_is_action(mgmt->frame_control))
@@ -1613,6 +1615,21 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
return RX_DROP_MONITOR;
ieee80211_process_measurement_req(sdata, mgmt, len);
break;
+ case WLAN_ACTION_SPCT_CHL_SWITCH:
+ if (len < (IEEE80211_MIN_ACTION_SIZE +
+ sizeof(mgmt->u.action.u.chan_switch)))
+ return RX_DROP_MONITOR;
+
+ bss = ieee80211_rx_bss_get(local, ifsta->bssid,
+ local->hw.conf.channel->center_freq,
+ ifsta->ssid, ifsta->ssid_len);
+ if (!bss)
+ return RX_DROP_MONITOR;
+
+ ieee80211_process_chanswitch(sdata,
+ &mgmt->u.action.u.chan_switch.sw_elem, bss);
+ ieee80211_rx_bss_put(local, bss);
+ break;
}
break;
default:
diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index f72bad6..22ad480 100644
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -84,3 +84,80 @@ void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
mgmt->sa, mgmt->bssid,
mgmt->u.action.u.measurement.dialog_token);
}
+
+void ieee80211_chswitch_work(struct work_struct *work)
+{
+ struct ieee80211_sub_if_data *sdata =
+ container_of(work, struct ieee80211_sub_if_data, u.sta.chswitch_work);
+ struct ieee80211_bss *bss;
+ struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+
+ if (!netif_running(sdata->dev))
+ return;
+
+ bss = ieee80211_rx_bss_get(sdata->local, ifsta->bssid,
+ sdata->local->hw.conf.channel->center_freq,
+ ifsta->ssid, ifsta->ssid_len);
+ if (!bss)
+ goto exit;
+
+ sdata->local->oper_channel = sdata->local->csa_channel;
+ if (!ieee80211_hw_config(sdata->local, IEEE80211_CONF_CHANGE_CHANNEL))
+ bss->freq = sdata->local->oper_channel->center_freq;
+
+ ieee80211_rx_bss_put(sdata->local, bss);
+exit:
+ ifsta->flags &= ~IEEE80211_STA_CSA_RECEIVED;
+ ieee80211_wake_queues_by_reason(&sdata->local->hw,
+ IEEE80211_QUEUE_STOP_REASON_CSA);
+}
+
+void ieee80211_chswitch_timer(unsigned long data)
+{
+ struct ieee80211_sub_if_data *sdata =
+ (struct ieee80211_sub_if_data *) data;
+ struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+
+ queue_work(sdata->local->hw.workqueue, &ifsta->chswitch_work);
+}
+
+void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_channel_sw_ie *sw_elem,
+ struct ieee80211_bss *bss)
+{
+ struct ieee80211_channel *new_ch;
+ struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+ int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num);
+
+ /* FIXME: Handle ADHOC later */
+ if (sdata->vif.type != NL80211_IFTYPE_STATION)
+ return;
+
+ if (ifsta->state != IEEE80211_STA_MLME_ASSOCIATED)
+ return;
+
+ if (sdata->local->sw_scanning || sdata->local->hw_scanning)
+ return;
+
+ /* Disregard subsequent beacons if we are already running a timer
+ processing a CSA */
+
+ if (ifsta->flags & IEEE80211_STA_CSA_RECEIVED)
+ return;
+
+ new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
+ if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED)
+ return;
+
+ sdata->local->csa_channel = new_ch;
+
+ if (sw_elem->count <= 1) {
+ queue_work(sdata->local->hw.workqueue, &ifsta->chswitch_work);
+ } else {
+ ieee80211_stop_queues_by_reason(&sdata->local->hw,
+ IEEE80211_QUEUE_STOP_REASON_CSA);
+ ifsta->flags |= IEEE80211_STA_CSA_RECEIVED;
+ mod_timer(&ifsta->chswitch_timer,
+ jiffies + msecs_to_jiffies(sw_elem->count * bss->beacon_int));
+ }
+}
--
1.6.0.3
On Mon, 2009-01-05 at 15:13 +0530, Sujith wrote:
[...]
Looks good to me, just one thought I had:
> + /* Disregard subsequent beacons if we are already running a timer
> + processing a CSA */
> +
> + if (ifsta->flags & IEEE80211_STA_CSA_RECEIVED)
> + return;
Should we verify that we're getting subsequent CSAs? Is it possible that
an AP drops the CSA element again and expects STAs to _not_ switch in
that case? Or, even if that is not possible, should we verify that
anyway?
johannes