[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, 5 insertions, 2 deletions

diff --git a/net/mac80211/ieee80211_ioctl.c b/net/mac80211/ieee80211_ioctl.c
index 9bc209b72d41..5918dd079e12 100644
--- a/net/mac80211/ieee80211_ioctl.c
+++ b/net/mac80211/ieee80211_ioctl.c
@@ -1180,7 +1180,10 @@ static int ieee80211_ioctl_prism2_param(struct net_device *dev,
                 break;
 
         case PRISM2_PARAM_CTS_PROTECT_ERP_FRAMES:
-                local->cts_protect_erp_frames = value;
+                if (sdata->type != IEEE80211_IF_TYPE_AP)
+                        ret = -ENOENT;
+                else
+                        sdata->use_protection = value;
                 break;
 
         case PRISM2_PARAM_PREAMBLE:
@@ -1303,7 +1306,7 @@ static int ieee80211_ioctl_get_prism2_param(struct net_device *dev,
                 break;
 
         case PRISM2_PARAM_CTS_PROTECT_ERP_FRAMES:
-                *param = local->cts_protect_erp_frames;
+                *param = sdata->use_protection;
                 break;
 
         case PRISM2_PARAM_PREAMBLE: