cfg80211: Use capability info to detect mesh beacons.

Mesh beacons no longer use all-zeroes BSSID.  Beacon frames for MBSS,
infrastructure BSS, or IBSS are differentiated by the Capability
Information field in the Beacon frame.  A mesh STA sets the ESS and IBSS
subfields to 0 in transmitted Beacon or Probe Response management
frames.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 12 insertions, 7 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index ee1c96a866cc..d527fb7bd67a 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1002,6 +1002,11 @@ struct ieee80211_ht_info {
 
 #define WLAN_CAPABILITY_ESS             (1<<0)
 #define WLAN_CAPABILITY_IBSS            (1<<1)
+
+/* A mesh STA sets the ESS and IBSS capability bits to zero */
+#define WLAN_CAPABILITY_IS_MBSS(cap)    \
+        (!((cap) & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)))
+
 #define WLAN_CAPABILITY_CF_POLLABLE     (1<<2)
 #define WLAN_CAPABILITY_CF_POLL_REQUEST (1<<3)
 #define WLAN_CAPABILITY_PRIVACY         (1<<4)
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index fbf6f33ae4d0..62e542a2b192 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -210,7 +210,7 @@ static bool is_mesh(struct cfg80211_bss *a,
 {
         const u8 *ie;
 
-        if (!is_zero_ether_addr(a->bssid))
+        if (!WLAN_CAPABILITY_IS_MBSS(a->capability))
                 return false;
 
         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
@@ -248,11 +248,7 @@ static int cmp_bss(struct cfg80211_bss *a,
         if (a->channel != b->channel)
                 return b->channel->center_freq - a->channel->center_freq;
 
-        r = memcmp(a->bssid, b->bssid, ETH_ALEN);
-        if (r)
-                return r;
-
-        if (is_zero_ether_addr(a->bssid)) {
+        if (WLAN_CAPABILITY_IS_MBSS(a->capability | b->capability)) {
                 r = cmp_ies(WLAN_EID_MESH_ID,
                             a->information_elements,
                             a->len_information_elements,
@@ -267,6 +263,10 @@ static int cmp_bss(struct cfg80211_bss *a,
                                b->len_information_elements);
         }
 
+        r = memcmp(a->bssid, b->bssid, ETH_ALEN);
+        if (r)
+                return r;
+
         return cmp_ies(WLAN_EID_SSID,
                        a->information_elements,
                        a->len_information_elements,
@@ -407,7 +407,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
 
         res->ts = jiffies;
 
-        if (is_zero_ether_addr(res->pub.bssid)) {
+        if (WLAN_CAPABILITY_IS_MBSS(res->pub.capability)) {
                 /* must be mesh, verify */
                 meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
                                           res->pub.information_elements,