[PATCH] Fixed BSSID step 1: Disallow to set multicast BSSID

["Alina Friedrichsen" <x-alina@xxxxxxx>]

Okay, here is the first of the five patches. After applying all of them you should be able to build/join huge city mesh networks (e.g. with the OLSR protocol) with the most of the mac80211 wireless drivers by setting a fixed BSSID in the ad hoc mode. (If you found no other bug/problem.) This was not specified in the original standard, but is a widely used de facto standard.

The first patch now completely disallow to set multicast MAC addresses as BSSID. The behavior before was really strange.

Signed-off-by: Alina Friedrichsen <x-alina@xxxxxxx>

diff -urN compat-wireless-2009-01-05.orig/net/mac80211/mlme.c compat-wireless-2009-01-05.work/net/mac80211/mlme.c
--- compat-wireless-2009-01-05.orig/net/mac80211/mlme.c	2009-01-06 01:38:05.000000000 +0100
+++ compat-wireless-2009-01-05/net/mac80211/mlme.c	2009-01-06 01:47:41.000000000 +0100
@@ -2576,11 +2576,16 @@
 {
 	struct ieee80211_if_sta *ifsta;
 	int res;
+	bool valid;
 
 	ifsta = &sdata->u.sta;
+	valid = is_valid_ether_addr(bssid);
 
 	if (memcmp(ifsta->bssid, bssid, ETH_ALEN) != 0) {
-		memcpy(ifsta->bssid, bssid, ETH_ALEN);
+		if(valid)
+			memcpy(ifsta->bssid, bssid, ETH_ALEN);
+		else
+			memset(ifsta->bssid, 0, ETH_ALEN);
 		res = 0;
 		/*
 		 * Hack! See also ieee80211_sta_set_ssid.
@@ -2594,7 +2599,7 @@
 		}
 	}
 
-	if (is_valid_ether_addr(bssid))
+	if (valid)
 		ifsta->flags |= IEEE80211_STA_BSSID_SET;
 	else
 		ifsta->flags &= ~IEEE80211_STA_BSSID_SET;

-- 
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diff -urN compat-wireless-2009-01-05.orig/net/mac80211/mlme.c compat-wireless-2009-01-05.work/net/mac80211/mlme.c
--- compat-wireless-2009-01-05.orig/net/mac80211/mlme.c	2009-01-06 01:38:05.000000000 +0100
+++ compat-wireless-2009-01-05/net/mac80211/mlme.c	2009-01-06 01:47:41.000000000 +0100
@@ -2576,11 +2576,16 @@
 {
 	struct ieee80211_if_sta *ifsta;
 	int res;
+	bool valid;
 
 	ifsta = &sdata->u.sta;
+	valid = is_valid_ether_addr(bssid);
 
 	if (memcmp(ifsta->bssid, bssid, ETH_ALEN) != 0) {
-		memcpy(ifsta->bssid, bssid, ETH_ALEN);
+		if(valid)
+			memcpy(ifsta->bssid, bssid, ETH_ALEN);
+		else
+			memset(ifsta->bssid, 0, ETH_ALEN);
 		res = 0;
 		/*
 		 * Hack! See also ieee80211_sta_set_ssid.
@@ -2594,7 +2599,7 @@
 		}
 	}
 
-	if (is_valid_ether_addr(bssid))
+	if (valid)
 		ifsta->flags |= IEEE80211_STA_BSSID_SET;
 	else
 		ifsta->flags &= ~IEEE80211_STA_BSSID_SET;