mac80211: reduce the amount of unnecessary traffic on cooked monitor interfaces
PATCH 1/1 mac80211: reduce the amount of unnecessary traffic on cooked monitor interfaces
In order to handle association and authentication in AP mode, hostapd needs access to the tx status info of its own frames through a cooked monitor interface. Without this patch the cooked monitor interfaces also passed on tx status information for packets from other virtual interfaces. This creates a significant performance issue on embedded system. Hostapd tries to work around this by installing a Linux Socket Filter that only captures the frames it's interested in, however data duplication and socket filter matching still uses up enough CPU cycles to be very noticeable on small systems. This patch ensures that tx status information of non-injected frames does not make it to cooked monitor interfaces.
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net/mac80211/main.c +5 -0
@@ -587,6 +587,11 @@ void ieee80211_tx_status(struct ieee8021if (!netif_running (sdata->dev))continue ; +if ((sdata->u.mntr_flags &MONITOR_FLAG_COOK_FRAMES ) && + !(info->flags &IEEE80211_TX_CTL_INJECTED ) && + (type ==IEEE80211_FTYPE_DATA )) +continue ; +if (prev_dev) { skb2 =skb_clone (skb,GFP_ATOMIC );if (skb2) {
Johannes Berg
maintainerQuoted 15 lines · Felix Fietkau
In order to handle association and authentication in AP mode, hostapd needs access to the tx status info of its own frames through a cooked monitor interface. Without this patch the cooked monitor interfaces also passed on tx status information for packets from other virtual interfaces. This creates a significant performance issue on embedded system. Hostapd tries to work around this by installing a Linux Socket Filter that only captures the frames it's interested in, however data duplication and socket filter matching still uses up enough CPU cycles to be very noticeable on small systems. This patch ensures that tx status information of non-injected frames does not make it to cooked monitor interfaces.
Signed-off-by Felix Fietkau <[email protected]>
net/mac80211/main.c void ieee80211_tx_status(struct ieee8021 · line 594
Quoted 5 lines
net/mac80211/main.c +5
-0+if ((sdata->u.mntr_flags &MONITOR_FLAG_COOK_FRAMES ) && + !(info->flags &IEEE80211_TX_CTL_INJECTED ) && + (type ==IEEE80211_FTYPE_DATA )) +continue ; +
This patch also breaks IEEE 802.11 compliance. :)
johannes
Johannes Berg
maintainerQuoted 7 lines · Johannes Berg
net/mac80211/main.c void ieee80211_tx_status(struct ieee8021 · line 594
Quoted 5 lines
net/mac80211/main.c +5
-0+if ((sdata->u.mntr_flags &MONITOR_FLAG_COOK_FRAMES ) && + !(info->flags &IEEE80211_TX_CTL_INJECTED ) && + (type ==IEEE80211_FTYPE_DATA )) +continue ; +This patch also breaks IEEE 802.11 compliance. :)
Oh no, it doesn't, wrong code path.
johannes