[net-next-2.6.git] / net / wireless / chan.c

/*
 * This file contains helper code to handle channel
 * settings and keeping track of what is possible at
 * any point in time.
 *
 * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
 */

#include <net/cfg80211.h>
#include "core.h"

struct ieee80211_channel *
rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
		  int freq, enum nl80211_channel_type channel_type)
{
	struct ieee80211_channel *chan;
	struct ieee80211_sta_ht_cap *ht_cap;

	chan = ieee80211_get_channel(&rdev->wiphy, freq);

	/* Primary channel not allowed */
	if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
		return NULL;

	if (channel_type == NL80211_CHAN_HT40MINUS &&
	    chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
		return NULL;
	else if (channel_type == NL80211_CHAN_HT40PLUS &&
		 chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
		return NULL;

	ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;

	if (channel_type != NL80211_CHAN_NO_HT) {
		if (!ht_cap->ht_supported)
			return NULL;

		if (channel_type != NL80211_CHAN_HT20 &&
		    (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
			return NULL;
	}

	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;
		break;
	case NL80211_CHAN_HT40MINUS:
		diff = -20;
		break;
	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)
{
	struct ieee80211_channel *chan;
	int result;

	if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR)
		wdev = NULL;

	if (wdev) {
		ASSERT_WDEV_LOCK(wdev);

		if (!netif_running(wdev->netdev))
			return -ENETDOWN;
	}

	if (!rdev->ops->set_channel)
		return -EOPNOTSUPP;

	chan = rdev_freq_to_chan(rdev, freq, channel_type);
	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);
	if (result)
		return result;

	if (wdev)
		wdev->channel = chan;

	return 0;
}
Commit	Line	Data
59bbb6f7 JB	1	/*
	2	* This file contains helper code to handle channel
	3	* settings and keeping track of what is possible at
	4	* any point in time.
	5	*
	6	* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
	7	*/
	8
	9	#include <net/cfg80211.h>
	10	#include "core.h"
	11
9588bbd5 JM	12	struct ieee80211_channel *
9588bbd5 JM	13	rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
59bbb6f7 JB	14	int freq, enum nl80211_channel_type channel_type)
	15	{
	16	struct ieee80211_channel *chan;
	17	struct ieee80211_sta_ht_cap *ht_cap;
59bbb6f7 JB	18
	19	chan = ieee80211_get_channel(&rdev->wiphy, freq);
	20
	21	/* Primary channel not allowed */
	22	if (!chan \|\| chan->flags & IEEE80211_CHAN_DISABLED)
9588bbd5	23	return NULL;
59bbb6f7 JB	24
	25	if (channel_type == NL80211_CHAN_HT40MINUS &&
	26	chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
9588bbd5	27	return NULL;
59bbb6f7 JB	28	else if (channel_type == NL80211_CHAN_HT40PLUS &&
59bbb6f7 JB	29	chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
9588bbd5	30	return NULL;
59bbb6f7 JB	31
	32	ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
	33
	34	if (channel_type != NL80211_CHAN_NO_HT) {
	35	if (!ht_cap->ht_supported)
9588bbd5	36	return NULL;
59bbb6f7	37
aed8e1f9 HS	38	if (channel_type != NL80211_CHAN_HT20 &&
	39	(!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) \|\|
	40	ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
9588bbd5	41	return NULL;
59bbb6f7 JB	42	}
59bbb6f7 JB	43
9588bbd5 JM	44	return chan;
	45	}
	46
9236d838 LR	47	static bool can_beacon_sec_chan(struct wiphy *wiphy,
	48	struct ieee80211_channel *chan,
	49	enum nl80211_channel_type channel_type)
	50	{
	51	struct ieee80211_channel *sec_chan;
	52	int diff;
	53
	54	switch (channel_type) {
	55	case NL80211_CHAN_HT40PLUS:
	56	diff = 20;
09a02fdb	57	break;
9236d838 LR	58	case NL80211_CHAN_HT40MINUS:
9236d838 LR	59	diff = -20;
09a02fdb	60	break;
9236d838 LR	61	default:
	62	return false;
	63	}
	64
	65	sec_chan = ieee80211_get_channel(wiphy, chan->center_freq + diff);
	66	if (!sec_chan)
	67	return false;
	68
	69	/* we'll need a DFS capability later */
	70	if (sec_chan->flags & (IEEE80211_CHAN_DISABLED \|
	71	IEEE80211_CHAN_PASSIVE_SCAN \|
	72	IEEE80211_CHAN_NO_IBSS \|
	73	IEEE80211_CHAN_RADAR))
	74	return false;
	75
	76	return true;
	77	}
	78
f444de05 JB	79	int cfg80211_set_freq(struct cfg80211_registered_device *rdev,
	80	struct wireless_dev *wdev, int freq,
	81	enum nl80211_channel_type channel_type)
9588bbd5 JM	82	{
	83	struct ieee80211_channel *chan;
	84	int result;
	85
9fbc630c	86	if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR)
f444de05 JB	87	wdev = NULL;
	88
	89	if (wdev) {
	90	ASSERT_WDEV_LOCK(wdev);
	91
	92	if (!netif_running(wdev->netdev))
	93	return -ENETDOWN;
	94	}
9588bbd5 JM	95
	96	if (!rdev->ops->set_channel)
	97	return -EOPNOTSUPP;
	98
	99	chan = rdev_freq_to_chan(rdev, freq, channel_type);
	100	if (!chan)
	101	return -EINVAL;
	102
9236d838 LR	103	/* Both channels should be able to initiate communication */
	104	if (wdev && (wdev->iftype == NL80211_IFTYPE_ADHOC \|\|
	105	wdev->iftype == NL80211_IFTYPE_AP \|\|
	106	wdev->iftype == NL80211_IFTYPE_AP_VLAN \|\|
	107	wdev->iftype == NL80211_IFTYPE_MESH_POINT \|\|
	108	wdev->iftype == NL80211_IFTYPE_P2P_GO)) {
	109	switch (channel_type) {
	110	case NL80211_CHAN_HT40PLUS:
	111	case NL80211_CHAN_HT40MINUS:
	112	if (!can_beacon_sec_chan(&rdev->wiphy, chan,
	113	channel_type)) {
	114	printk(KERN_DEBUG
	115	"cfg80211: Secondary channel not "
	116	"allowed to initiate communication\n");
	117	return -EINVAL;
	118	}
	119	break;
	120	default:
	121	break;
	122	}
	123	}
	124
f444de05 JB	125	result = rdev->ops->set_channel(&rdev->wiphy,
	126	wdev ? wdev->netdev : NULL,
	127	chan, channel_type);
59bbb6f7 JB	128	if (result)
	129	return result;
	130
f444de05 JB	131	if (wdev)
f444de05 JB	132	wdev->channel = chan;
59bbb6f7 JB	133
	134	return 0;
	135	}