[patch 6/7] mac80211: allow only one IBSS interface
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2007-09-26 15:55:11
Consider the case of multiple virtual IBSS interfaces trying to join the same IBSS. They wouldn't see beacons that the other virtual interface sent of course so this leads to problems. Disallow it. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> --- net/mac80211/ieee80211.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-)
--- wireless-dev.orig/net/mac80211/ieee80211.c 2007-09-26 17:21:42.667337342 +0200
+++ wireless-dev/net/mac80211/ieee80211.c 2007-09-26 17:21:51.317337342 +0200@@ -170,8 +170,25 @@ static int ieee80211_open(struct net_dev list_for_each_entry(nsdata, &local->interfaces, list) { struct net_device *ndev = nsdata->dev; - if (ndev != dev && ndev != local->mdev && netif_running(ndev) && - compare_ether_addr(dev->dev_addr, ndev->dev_addr) == 0) { + if (ndev != dev && ndev != local->mdev && + netif_running(ndev)) { + /* + * We really only support one IBSS interface, think + * what would happen if they tried to be in the same + * BSS. + */ + if (sdata->type == IEEE80211_IF_TYPE_IBSS && + nsdata->type == IEEE80211_IF_TYPE_IBSS && + netif_running(nsdata->dev)) + return -EBUSY; + + /* + * The remaining checks are only done for devices + * with the same MAC address. + */ + if (compare_ether_addr(dev->dev_addr, ndev->dev_addr)) + continue; + /* * check whether it may have the same address */
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