[PATCH] mac80211: improved 802.11g CTS protection

Currently, CTS protection is partially implemented twice:
 1. via prism2 ioctls, only used by hostapd
 2. via STA beacon parsing, recorded in sta.use_protection but never used
    (other than printed in debugfs)

Protection control should be implemented on a per-subif basis. For example,
a single physical device may be running a soft AP on one channel, and a STA
on another. The AP interface should use protection based on what hostapd told
it, and the STA interface should use protection based on beacon parsing.
These should operate independantly: one subif using protection should not
influence the other.

To implement this, I moved the use_protection flag into ieee80211_sub_if_data
and removed the device-global cts_protect_erp_frames flag.

I also made the PRISM2_PARAM_CTS_PROTECT_ERP_FRAMES write operation only
available for AP interfaces, to avoid any possibility of the user messing with
the behaviour of a STA.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index df6c410de16..ba2bf8f0a34 100644
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -316,12 +316,11 @@ static void ieee80211_sta_wmm_params(struct net_device *dev,
 
 static void ieee80211_handle_erp_ie(struct net_device *dev, u8 erp_value)
 {
-	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
 	int use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
 
-	if (use_protection != !!ifsta->use_protection) {
+	if (use_protection != sdata->use_protection) {
 		if (net_ratelimit()) {
 			printk(KERN_DEBUG "%s: CTS protection %s (BSSID="
 			       MAC_FMT ")\n",
@@ -329,8 +328,7 @@ static void ieee80211_handle_erp_ie(struct net_device *dev, u8 erp_value)
 			       use_protection ? "enabled" : "disabled",
 			       MAC_ARG(ifsta->bssid));
 		}
-		ifsta->use_protection = use_protection ? 1 : 0;
-		local->cts_protect_erp_frames = use_protection;
+		sdata->use_protection = use_protection;
 	}
 }
 
@@ -390,6 +388,7 @@ static void ieee80211_set_associated(struct net_device *dev,
 				     struct ieee80211_if_sta *ifsta, int assoc)
 {
 	union iwreq_data wrqu;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
 	if (ifsta->associated == assoc)
 		return;
@@ -417,6 +416,7 @@ static void ieee80211_set_associated(struct net_device *dev,
 		ieee80211_sta_send_associnfo(dev, ifsta);
 	} else {
 		netif_carrier_off(dev);
+		sdata->use_protection = 0;
 		memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN);
 	}
 	wrqu.ap_addr.sa_family = ARPHRD_ETHER;