 09a02fdb91
			
		
	
	
	09a02fdb91
	
	
	
		
			
			This follows wireless-testing 9236d838c9
("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 <mark@moxienet.com>
Cc: stable@kernel.org
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com
Signed-off-by: John W. Linville <linville@tuxdriver.com>
		
	
			
		
			
				
	
	
		
			135 lines
		
	
	
	
		
			3.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			135 lines
		
	
	
	
		
			3.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * This file contains helper code to handle channel
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|  * settings and keeping track of what is possible at
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|  * any point in time.
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|  *
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|  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
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|  */
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| 
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| #include <net/cfg80211.h>
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| #include "core.h"
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| 
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| struct ieee80211_channel *
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| rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
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| 		  int freq, enum nl80211_channel_type channel_type)
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| {
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| 	struct ieee80211_channel *chan;
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| 	struct ieee80211_sta_ht_cap *ht_cap;
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| 
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| 	chan = ieee80211_get_channel(&rdev->wiphy, freq);
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| 
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| 	/* Primary channel not allowed */
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| 	if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
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| 		return NULL;
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| 
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| 	if (channel_type == NL80211_CHAN_HT40MINUS &&
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| 	    chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
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| 		return NULL;
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| 	else if (channel_type == NL80211_CHAN_HT40PLUS &&
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| 		 chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
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| 		return NULL;
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| 
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| 	ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
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| 
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| 	if (channel_type != NL80211_CHAN_NO_HT) {
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| 		if (!ht_cap->ht_supported)
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| 			return NULL;
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| 
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| 		if (channel_type != NL80211_CHAN_HT20 &&
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| 		    (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
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| 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
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| 			return NULL;
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| 	}
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| 
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| 	return chan;
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| }
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| 
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| static bool can_beacon_sec_chan(struct wiphy *wiphy,
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| 				struct ieee80211_channel *chan,
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| 				enum nl80211_channel_type channel_type)
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| {
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| 	struct ieee80211_channel *sec_chan;
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| 	int diff;
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| 
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| 	switch (channel_type) {
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| 	case NL80211_CHAN_HT40PLUS:
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| 		diff = 20;
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| 		break;
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| 	case NL80211_CHAN_HT40MINUS:
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| 		diff = -20;
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| 		break;
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| 	default:
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| 		return false;
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| 	}
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| 
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| 	sec_chan = ieee80211_get_channel(wiphy, chan->center_freq + diff);
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| 	if (!sec_chan)
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| 		return false;
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| 
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| 	/* we'll need a DFS capability later */
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| 	if (sec_chan->flags & (IEEE80211_CHAN_DISABLED |
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| 			       IEEE80211_CHAN_PASSIVE_SCAN |
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| 			       IEEE80211_CHAN_NO_IBSS |
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| 			       IEEE80211_CHAN_RADAR))
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| 		return false;
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| 
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| 	return true;
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| }
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| 
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| int cfg80211_set_freq(struct cfg80211_registered_device *rdev,
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| 		      struct wireless_dev *wdev, int freq,
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| 		      enum nl80211_channel_type channel_type)
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| {
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| 	struct ieee80211_channel *chan;
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| 	int result;
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| 
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| 	if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR)
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| 		wdev = NULL;
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| 
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| 	if (wdev) {
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| 		ASSERT_WDEV_LOCK(wdev);
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| 
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| 		if (!netif_running(wdev->netdev))
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| 			return -ENETDOWN;
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| 	}
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| 
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| 	if (!rdev->ops->set_channel)
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| 		return -EOPNOTSUPP;
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| 
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| 	chan = rdev_freq_to_chan(rdev, freq, channel_type);
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| 	if (!chan)
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| 		return -EINVAL;
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| 
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| 	/* Both channels should be able to initiate communication */
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| 	if (wdev && (wdev->iftype == NL80211_IFTYPE_ADHOC ||
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| 		     wdev->iftype == NL80211_IFTYPE_AP ||
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| 		     wdev->iftype == NL80211_IFTYPE_AP_VLAN ||
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| 		     wdev->iftype == NL80211_IFTYPE_MESH_POINT ||
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| 		     wdev->iftype == NL80211_IFTYPE_P2P_GO)) {
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| 		switch (channel_type) {
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| 		case NL80211_CHAN_HT40PLUS:
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| 		case NL80211_CHAN_HT40MINUS:
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| 			if (!can_beacon_sec_chan(&rdev->wiphy, chan,
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| 						 channel_type)) {
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| 				printk(KERN_DEBUG
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| 				       "cfg80211: Secondary channel not "
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| 				       "allowed to initiate communication\n");
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| 				return -EINVAL;
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| 			}
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| 			break;
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| 		default:
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| 			break;
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| 		}
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| 	}
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| 
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| 	result = rdev->ops->set_channel(&rdev->wiphy,
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| 					wdev ? wdev->netdev : NULL,
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| 					chan, channel_type);
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| 	if (result)
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| 		return result;
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| 
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| 	if (wdev)
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| 		wdev->channel = chan;
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| 
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| 	return 0;
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| }
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