[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 df6c410de161..ba2bf8f0a347 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;