Currently, multicast data packets are dropped on AP interfaces if
there are no authorized stations connected. This avoids superflous
data packets to be transmitted on air.
But when using AP_VLAN, this does not happen, as the current check does
not apply to AP_VLAN interfaces. Though, there can easily be more AP_VLAN
interfaces on an AP resulting in more multicast data frames. This is
especially true since hostapd does not remove no-longer-used AP_VLAN
interfaces and bridges.
In order to filter on AP_VLAN interfaces, a per AP_VLAN interface
counter is required (in constrast to the counter on the AP interface
counting the stations on all related AP_VLAN interfaces as well).
If there are multicast data frames on the AP interface and authorized
stations only on the related AP_VLAN interfaces, these multicast data
frames on the AP interface still won't be filtered.
This is just left unchanged by this patch.
Signed-off-by: Michael Braun <[email protected]>
---
net/mac80211/cfg.c | 12 ++++++++++++
net/mac80211/debugfs_netdev.c | 9 +++++++++
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/sta_info.c | 17 +++++++++++++++++
net/mac80211/tx.c | 8 ++++++++
5 files changed, 47 insertions(+)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 74f509c..53db0c3 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1360,6 +1360,18 @@ static int ieee80211_change_station(struct wiphy *wiphy,
prev_4addr = true;
}
+ if (sta->sta_state == IEEE80211_STA_AUTHORIZED &&
+ sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ !sta->sdata->u.vlan.sta &&
+ sta->sdata != vlansdata)
+ atomic_dec(&sta->sdata->u.vlan.num_mcast_sta);
+
+ if (sta->sta_state == IEEE80211_STA_AUTHORIZED &&
+ vlansdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ !vlansdata->u.vlan.sta &&
+ sta->sdata != vlansdata)
+ atomic_inc(&vlansdata->u.vlan.num_mcast_sta);
+
sta->sdata = vlansdata;
if (sta->sta_state == IEEE80211_STA_AUTHORIZED &&
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index c68896a..71b71e2 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -428,6 +428,7 @@ IEEE80211_IF_FILE_RW(uapsd_max_sp_len);
IEEE80211_IF_FILE(num_mcast_sta, u.ap.num_mcast_sta, ATOMIC);
IEEE80211_IF_FILE(num_sta_ps, u.ap.ps.num_sta_ps, ATOMIC);
IEEE80211_IF_FILE(dtim_count, u.ap.ps.dtim_count, DEC);
+IEEE80211_IF_FILE(vlan_num_mcast_sta, u.vlan.num_mcast_sta, ATOMIC);
static ssize_t ieee80211_if_fmt_num_buffered_multicast(
const struct ieee80211_sub_if_data *sdata, char *buf, int buflen)
@@ -594,6 +595,11 @@ static void add_ap_files(struct ieee80211_sub_if_data *sdata)
DEBUGFS_ADD_MODE(tkip_mic_test, 0200);
}
+static void add_vlan_files(struct ieee80211_sub_if_data *sdata)
+{
+ DEBUGFS_ADD(vlan_num_mcast_sta);
+}
+
static void add_ibss_files(struct ieee80211_sub_if_data *sdata)
{
DEBUGFS_ADD_MODE(tsf, 0600);
@@ -697,6 +703,9 @@ static void add_files(struct ieee80211_sub_if_data *sdata)
case NL80211_IFTYPE_AP:
add_ap_files(sdata);
break;
+ case NL80211_IFTYPE_AP_VLAN:
+ add_vlan_files(sdata);
+ break;
case NL80211_IFTYPE_WDS:
add_wds_files(sdata);
break;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8d53d65..722ad28 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -305,6 +305,7 @@ struct ieee80211_if_vlan {
/* used for all tx if the VLAN is configured to 4-addr mode */
struct sta_info __rcu *sta;
+ atomic_t num_mcast_sta; /* number of stations receiving multicast */
};
struct mesh_stats {
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 00ca8dc..68f9d2b 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -143,6 +143,17 @@ static void __cleanup_single_sta(struct sta_info *sta)
ieee80211_purge_tx_queue(&local->hw, &tid_tx->pending);
kfree(tid_tx);
}
+
+ if (test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
+ if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
+ (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ !sta->sdata->u.vlan.sta))
+ atomic_dec(&sta->sdata->bss->num_mcast_sta);
+ if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ !sta->sdata->u.vlan.sta)
+ atomic_dec(&sta->sdata->u.vlan.num_mcast_sta);
+ clear_sta_flag(sta, WLAN_STA_AUTHORIZED);
+ }
}
static void cleanup_single_sta(struct sta_info *sta)
@@ -1694,6 +1705,9 @@ int sta_info_move_state(struct sta_info *sta,
(sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
!sta->sdata->u.vlan.sta))
atomic_dec(&sta->sdata->bss->num_mcast_sta);
+ if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ !sta->sdata->u.vlan.sta)
+ atomic_dec(&sta->sdata->u.vlan.num_mcast_sta);
clear_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
}
break;
@@ -1703,6 +1717,9 @@ int sta_info_move_state(struct sta_info *sta,
(sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
!sta->sdata->u.vlan.sta))
atomic_inc(&sta->sdata->bss->num_mcast_sta);
+ if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ !sta->sdata->u.vlan.sta)
+ atomic_inc(&sta->sdata->u.vlan.num_mcast_sta);
set_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
}
break;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 07bd8db..ff10e00 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -330,6 +330,14 @@ ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
* frames.
*/
return TX_DROP;
+ } else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ ieee80211_is_data(hdr->frame_control) &&
+ !atomic_read(&tx->sdata->u.vlan.num_mcast_sta))) {
+ /*
+ * No associated STAs - no need to send multicast
+ * frames.
+ */
+ return TX_DROP;
}
return TX_CONTINUE;
--
1.9.1
On Tue, 2015-03-17 at 20:30 +0100, Michael Braun wrote:
> Currently, multicast data packets are dropped on AP interfaces if
> there are no authorized stations connected. This avoids superflous
typo: superfluous
> data packets to be transmitted on air.
>
> But when using AP_VLAN, this does not happen, as the current check does
> not apply to AP_VLAN interfaces. Though, there can easily be more AP_VLAN
> interfaces on an AP resulting in more multicast data frames. This is
> especially true since hostapd does not remove no-longer-used AP_VLAN
> interfaces and bridges.
>
> In order to filter on AP_VLAN interfaces, a per AP_VLAN interface
> counter is required (in constrast to the counter on the AP interface
typo: contrast
> + if (sta->sta_state == IEEE80211_STA_AUTHORIZED &&
> + sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> + !sta->sdata->u.vlan.sta &&
> + sta->sdata != vlansdata)
> + atomic_dec(&sta->sdata->u.vlan.num_mcast_sta);
> +
> + if (sta->sta_state == IEEE80211_STA_AUTHORIZED &&
> + vlansdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
Hmm. Can this ever be false?
> +++ b/net/mac80211/sta_info.c
> @@ -143,6 +143,17 @@ static void __cleanup_single_sta(struct sta_info *sta)
> ieee80211_purge_tx_queue(&local->hw, &tid_tx->pending);
> kfree(tid_tx);
> }
> +
> + if (test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
> + if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
> + (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> + !sta->sdata->u.vlan.sta))
> + atomic_dec(&sta->sdata->bss->num_mcast_sta);
> + if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> + !sta->sdata->u.vlan.sta)
> + atomic_dec(&sta->sdata->u.vlan.num_mcast_sta);
> + clear_sta_flag(sta, WLAN_STA_AUTHORIZED);
> + }
> }
The new clear_sta_flag() here seems rather wrong to me?
> @@ -1694,6 +1705,9 @@ int sta_info_move_state(struct sta_info *sta,
> (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> !sta->sdata->u.vlan.sta))
> atomic_dec(&sta->sdata->bss->num_mcast_sta);
> + if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> + !sta->sdata->u.vlan.sta)
> + atomic_dec(&sta->sdata->u.vlan.num_mcast_sta);
> clear_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
> @@ -1703,6 +1717,9 @@ int sta_info_move_state(struct sta_info *sta,
> (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> !sta->sdata->u.vlan.sta))
> atomic_inc(&sta->sdata->bss->num_mcast_sta);
> + if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
> + !sta->sdata->u.vlan.sta)
> + atomic_inc(&sta->sdata->u.vlan.num_mcast_sta);
It seems to me that perhaps we should split this into two new
subfunctions or so to be able to refactor this code? After all, you have
exactly the same conditions here ...
johannes