From 9236d838c920e90708570d9bbd7bb82d30a38130 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Fri, 12 Nov 2010 16:31:23 -0800 Subject: cfg80211: fix extension channel checks to initiate communication When operating in a mode that initiates communication and using HT40 we should fail if we cannot use both primary and secondary channels to initiate communication. Our current ht40 allowmap only covers STA mode of operation, for beaconing modes we need a check on the fly as the mode of operation is dynamic and there other flags other than disable which we should read to check if we can initiate communication. Do not allow for initiating communication if our secondary HT40 channel has is either disabled, has a passive scan flag, a no-ibss flag or is a radar channel. Userspace now has similar checks but this is also needed in-kernel. Reported-by: Jouni Malinen Cc: stable@kernel.org Signed-off-by: Luis R. Rodriguez Signed-off-by: John W. Linville --- net/wireless/chan.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) (limited to 'net') diff --git a/net/wireless/chan.c b/net/wireless/chan.c index d0c92dddb26b..c8d190d911e4 100644 --- a/net/wireless/chan.c +++ b/net/wireless/chan.c @@ -44,6 +44,36 @@ rdev_freq_to_chan(struct cfg80211_registered_device *rdev, return chan; } +static bool can_beacon_sec_chan(struct wiphy *wiphy, + struct ieee80211_channel *chan, + enum nl80211_channel_type channel_type) +{ + struct ieee80211_channel *sec_chan; + int diff; + + switch (channel_type) { + case NL80211_CHAN_HT40PLUS: + diff = 20; + case NL80211_CHAN_HT40MINUS: + diff = -20; + default: + return false; + } + + sec_chan = ieee80211_get_channel(wiphy, chan->center_freq + diff); + if (!sec_chan) + return false; + + /* we'll need a DFS capability later */ + if (sec_chan->flags & (IEEE80211_CHAN_DISABLED | + IEEE80211_CHAN_PASSIVE_SCAN | + IEEE80211_CHAN_NO_IBSS | + IEEE80211_CHAN_RADAR)) + return false; + + return true; +} + int cfg80211_set_freq(struct cfg80211_registered_device *rdev, struct wireless_dev *wdev, int freq, enum nl80211_channel_type channel_type) @@ -68,6 +98,28 @@ int cfg80211_set_freq(struct cfg80211_registered_device *rdev, if (!chan) return -EINVAL; + /* Both channels should be able to initiate communication */ + if (wdev && (wdev->iftype == NL80211_IFTYPE_ADHOC || + wdev->iftype == NL80211_IFTYPE_AP || + wdev->iftype == NL80211_IFTYPE_AP_VLAN || + wdev->iftype == NL80211_IFTYPE_MESH_POINT || + wdev->iftype == NL80211_IFTYPE_P2P_GO)) { + switch (channel_type) { + case NL80211_CHAN_HT40PLUS: + case NL80211_CHAN_HT40MINUS: + if (!can_beacon_sec_chan(&rdev->wiphy, chan, + channel_type)) { + printk(KERN_DEBUG + "cfg80211: Secondary channel not " + "allowed to initiate communication\n"); + return -EINVAL; + } + break; + default: + break; + } + } + result = rdev->ops->set_channel(&rdev->wiphy, wdev ? wdev->netdev : NULL, chan, channel_type); -- cgit v1.2.3-70-g09d2 From 09a02fdb919876c01e8f05960750a418b3f7fa48 Mon Sep 17 00:00:00 2001 From: Mark Mentovai Date: Wed, 17 Nov 2010 16:34:37 -0500 Subject: cfg80211: fix can_beacon_sec_chan, reenable HT40 This follows wireless-testing 9236d838c920e90708570d9bbd7bb82d30a38130 ("cfg80211: fix extension channel checks to initiate communication") and fixes accidental case fall-through. Without this fix, HT40 is entirely blocked. Signed-off-by: Mark Mentovai Cc: stable@kernel.org Acked-by: Luis R. Rodriguez --- net/wireless/chan.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net') diff --git a/net/wireless/chan.c b/net/wireless/chan.c index c8d190d911e4..17cd0c04d139 100644 --- a/net/wireless/chan.c +++ b/net/wireless/chan.c @@ -54,8 +54,10 @@ static bool can_beacon_sec_chan(struct wiphy *wiphy, switch (channel_type) { case NL80211_CHAN_HT40PLUS: diff = 20; + break; case NL80211_CHAN_HT40MINUS: diff = -20; + break; default: return false; } -- cgit v1.2.3-70-g09d2