[deliverable/linux.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 <linux/export.h>
#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;
}

bool cfg80211_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 true;
	}

	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;
}
EXPORT_SYMBOL(cfg80211_can_beacon_sec_chan);

int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
				 int freq, enum nl80211_channel_type chantype)
{
	struct ieee80211_channel *chan;

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

	chan = rdev_freq_to_chan(rdev, freq, chantype);
	if (!chan)
		return -EINVAL;

	return rdev->ops->set_monitor_channel(&rdev->wiphy, chan, chantype);
}
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
54858ee5	9	#include <linux/export.h>
59bbb6f7 JB	10	#include <net/cfg80211.h>
	11	#include "core.h"
	12
9588bbd5 JM	13	struct ieee80211_channel *
9588bbd5 JM	14	rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
59bbb6f7 JB	15	int freq, enum nl80211_channel_type channel_type)
	16	{
	17	struct ieee80211_channel *chan;
	18	struct ieee80211_sta_ht_cap *ht_cap;
59bbb6f7 JB	19
	20	chan = ieee80211_get_channel(&rdev->wiphy, freq);
	21
	22	/* Primary channel not allowed */
	23	if (!chan \|\| chan->flags & IEEE80211_CHAN_DISABLED)
9588bbd5	24	return NULL;
59bbb6f7 JB	25
	26	if (channel_type == NL80211_CHAN_HT40MINUS &&
	27	chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
9588bbd5	28	return NULL;
59bbb6f7 JB	29	else if (channel_type == NL80211_CHAN_HT40PLUS &&
59bbb6f7 JB	30	chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
9588bbd5	31	return NULL;
59bbb6f7 JB	32
	33	ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
	34
	35	if (channel_type != NL80211_CHAN_NO_HT) {
	36	if (!ht_cap->ht_supported)
9588bbd5	37	return NULL;
59bbb6f7	38
aed8e1f9 HS	39	if (channel_type != NL80211_CHAN_HT20 &&
	40	(!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) \|\|
	41	ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
9588bbd5	42	return NULL;
59bbb6f7 JB	43	}
59bbb6f7 JB	44
9588bbd5 JM	45	return chan;
	46	}
	47
294a20e0	48	bool cfg80211_can_beacon_sec_chan(struct wiphy *wiphy,
54858ee5 AS	49	struct ieee80211_channel *chan,
54858ee5 AS	50	enum nl80211_channel_type channel_type)
9236d838 LR	51	{
	52	struct ieee80211_channel *sec_chan;
	53	int diff;
	54
	55	switch (channel_type) {
	56	case NL80211_CHAN_HT40PLUS:
	57	diff = 20;
09a02fdb	58	break;
9236d838 LR	59	case NL80211_CHAN_HT40MINUS:
9236d838 LR	60	diff = -20;
09a02fdb	61	break;
9236d838	62	default:
d58e7e37	63	return true;
9236d838 LR	64	}
	65
	66	sec_chan = ieee80211_get_channel(wiphy, chan->center_freq + diff);
	67	if (!sec_chan)
	68	return false;
	69
	70	/* we'll need a DFS capability later */
	71	if (sec_chan->flags & (IEEE80211_CHAN_DISABLED \|
	72	IEEE80211_CHAN_PASSIVE_SCAN \|
	73	IEEE80211_CHAN_NO_IBSS \|
	74	IEEE80211_CHAN_RADAR))
	75	return false;
	76
	77	return true;
	78	}
54858ee5	79	EXPORT_SYMBOL(cfg80211_can_beacon_sec_chan);
9236d838	80
e8c9bd5b JB	81	int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
e8c9bd5b JB	82	int freq, enum nl80211_channel_type chantype)
9588bbd5 JM	83	{
9588bbd5 JM	84	struct ieee80211_channel *chan;
9588bbd5	85
e8c9bd5b	86	if (!rdev->ops->set_monitor_channel)
9588bbd5 JM	87	return -EOPNOTSUPP;
9588bbd5 JM	88
e8c9bd5b	89	chan = rdev_freq_to_chan(rdev, freq, chantype);
9588bbd5 JM	90	if (!chan)
	91	return -EINVAL;
	92
e8c9bd5b	93	return rdev->ops->set_monitor_channel(&rdev->wiphy, chan, chantype);
59bbb6f7	94	}