[linux-2.6-block.git] / net / mac80211 / chan.c

/*
 * mac80211 - channel management
 */

#include <linux/nl80211.h>
#include <net/cfg80211.h>
#include "ieee80211_i.h"

static enum ieee80211_chan_mode
__ieee80211_get_channel_mode(struct ieee80211_local *local,
			     struct ieee80211_sub_if_data *ignore)
{
	struct ieee80211_sub_if_data *sdata;

	lockdep_assert_held(&local->iflist_mtx);

	list_for_each_entry(sdata, &local->interfaces, list) {
		if (sdata == ignore)
			continue;

		if (!ieee80211_sdata_running(sdata))
			continue;

		switch (sdata->vif.type) {
		case NL80211_IFTYPE_MONITOR:
			continue;
		case NL80211_IFTYPE_STATION:
			if (!sdata->u.mgd.associated)
				continue;
			break;
		case NL80211_IFTYPE_ADHOC:
			if (!sdata->u.ibss.ssid_len)
				continue;
			if (!sdata->u.ibss.fixed_channel)
				return CHAN_MODE_HOPPING;
			break;
		case NL80211_IFTYPE_AP_VLAN:
			/* will also have _AP interface */
			continue;
		case NL80211_IFTYPE_AP:
			if (!sdata->u.ap.beacon)
				continue;
			break;
		case NL80211_IFTYPE_MESH_POINT:
			if (!sdata->wdev.mesh_id_len)
				continue;
			break;
		default:
			break;
		}

		return CHAN_MODE_FIXED;
	}

	return CHAN_MODE_UNDEFINED;
}

enum ieee80211_chan_mode
ieee80211_get_channel_mode(struct ieee80211_local *local,
			   struct ieee80211_sub_if_data *ignore)
{
	enum ieee80211_chan_mode mode;

	mutex_lock(&local->iflist_mtx);
	mode = __ieee80211_get_channel_mode(local, ignore);
	mutex_unlock(&local->iflist_mtx);

	return mode;
}

static enum nl80211_channel_type
ieee80211_get_superchan(struct ieee80211_local *local,
			struct ieee80211_sub_if_data *sdata)
{
	enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
	struct ieee80211_sub_if_data *tmp;

	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(tmp, &local->interfaces, list) {
		if (tmp == sdata)
			continue;

		if (!ieee80211_sdata_running(tmp))
			continue;

		switch (tmp->vif.bss_conf.channel_type) {
		case NL80211_CHAN_NO_HT:
		case NL80211_CHAN_HT20:
			if (superchan > tmp->vif.bss_conf.channel_type)
				break;

			superchan = tmp->vif.bss_conf.channel_type;
			break;
		case NL80211_CHAN_HT40PLUS:
			WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
			superchan = NL80211_CHAN_HT40PLUS;
			break;
		case NL80211_CHAN_HT40MINUS:
			WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
			superchan = NL80211_CHAN_HT40MINUS;
			break;
		}
	}
	mutex_unlock(&local->iflist_mtx);

	return superchan;
}

static bool
ieee80211_channel_types_are_compatible(enum nl80211_channel_type chantype1,
				       enum nl80211_channel_type chantype2,
				       enum nl80211_channel_type *compat)
{
	/*
	 * start out with chantype1 being the result,
	 * overwriting later if needed
	 */
	if (compat)
		*compat = chantype1;

	switch (chantype1) {
	case NL80211_CHAN_NO_HT:
		if (compat)
			*compat = chantype2;
		break;
	case NL80211_CHAN_HT20:
		/*
		 * allow any change that doesn't go to no-HT
		 * (if it already is no-HT no change is needed)
		 */
		if (chantype2 == NL80211_CHAN_NO_HT)
			break;
		if (compat)
			*compat = chantype2;
		break;
	case NL80211_CHAN_HT40PLUS:
	case NL80211_CHAN_HT40MINUS:
		/* allow smaller bandwidth and same */
		if (chantype2 == NL80211_CHAN_NO_HT)
			break;
		if (chantype2 == NL80211_CHAN_HT20)
			break;
		if (chantype2 == chantype1)
			break;
		return false;
	}

	return true;
}

bool ieee80211_set_channel_type(struct ieee80211_local *local,
				struct ieee80211_sub_if_data *sdata,
				enum nl80211_channel_type chantype)
{
	enum nl80211_channel_type superchan;
	enum nl80211_channel_type compatchan;

	superchan = ieee80211_get_superchan(local, sdata);
	if (!ieee80211_channel_types_are_compatible(superchan, chantype,
						    &compatchan))
		return false;

	local->_oper_channel_type = compatchan;

	if (sdata)
		sdata->vif.bss_conf.channel_type = chantype;

	return true;

}
Commit	Line	Data
f444de05 JB	1	/*
	2	* mac80211 - channel management
	3	*/
	4
0aaffa9b	5	#include <linux/nl80211.h>
3117bbdb	6	#include <net/cfg80211.h>
f444de05 JB	7	#include "ieee80211_i.h"
f444de05 JB	8
368a07d2	9	static enum ieee80211_chan_mode
f444de05 JB	10	__ieee80211_get_channel_mode(struct ieee80211_local *local,
	11	struct ieee80211_sub_if_data *ignore)
	12	{
	13	struct ieee80211_sub_if_data *sdata;
	14
46a5ebaf	15	lockdep_assert_held(&local->iflist_mtx);
f444de05 JB	16
	17	list_for_each_entry(sdata, &local->interfaces, list) {
	18	if (sdata == ignore)
	19	continue;
	20
	21	if (!ieee80211_sdata_running(sdata))
	22	continue;
	23
e9980e6d JB	24	switch (sdata->vif.type) {
e9980e6d JB	25	case NL80211_IFTYPE_MONITOR:
f444de05	26	continue;
e9980e6d JB	27	case NL80211_IFTYPE_STATION:
	28	if (!sdata->u.mgd.associated)
	29	continue;
	30	break;
	31	case NL80211_IFTYPE_ADHOC:
f444de05 JB	32	if (!sdata->u.ibss.ssid_len)
	33	continue;
	34	if (!sdata->u.ibss.fixed_channel)
	35	return CHAN_MODE_HOPPING;
e9980e6d JB	36	break;
	37	case NL80211_IFTYPE_AP_VLAN:
	38	/* will also have _AP interface */
f444de05	39	continue;
e9980e6d JB	40	case NL80211_IFTYPE_AP:
	41	if (!sdata->u.ap.beacon)
	42	continue;
	43	break;
be0f4237 TP	44	case NL80211_IFTYPE_MESH_POINT:
	45	if (!sdata->wdev.mesh_id_len)
	46	continue;
	47	break;
e9980e6d JB	48	default:
	49	break;
	50	}
f444de05 JB	51
	52	return CHAN_MODE_FIXED;
	53	}
	54
	55	return CHAN_MODE_UNDEFINED;
	56	}
	57
	58	enum ieee80211_chan_mode
	59	ieee80211_get_channel_mode(struct ieee80211_local *local,
	60	struct ieee80211_sub_if_data *ignore)
	61	{
	62	enum ieee80211_chan_mode mode;
	63
	64	mutex_lock(&local->iflist_mtx);
	65	mode = __ieee80211_get_channel_mode(local, ignore);
	66	mutex_unlock(&local->iflist_mtx);
	67
	68	return mode;
	69	}
0aaffa9b	70
23a85b45 MK	71	static enum nl80211_channel_type
	72	ieee80211_get_superchan(struct ieee80211_local *local,
	73	struct ieee80211_sub_if_data *sdata)
0aaffa9b	74	{
0aaffa9b	75	enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
23a85b45	76	struct ieee80211_sub_if_data *tmp;
0aaffa9b JB	77
0aaffa9b JB	78	mutex_lock(&local->iflist_mtx);
0aaffa9b JB	79	list_for_each_entry(tmp, &local->interfaces, list) {
	80	if (tmp == sdata)
	81	continue;
	82
	83	if (!ieee80211_sdata_running(tmp))
	84	continue;
	85
	86	switch (tmp->vif.bss_conf.channel_type) {
	87	case NL80211_CHAN_NO_HT:
	88	case NL80211_CHAN_HT20:
9db372fd FF	89	if (superchan > tmp->vif.bss_conf.channel_type)
	90	break;
	91
0aaffa9b JB	92	superchan = tmp->vif.bss_conf.channel_type;
	93	break;
	94	case NL80211_CHAN_HT40PLUS:
	95	WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
	96	superchan = NL80211_CHAN_HT40PLUS;
	97	break;
	98	case NL80211_CHAN_HT40MINUS:
	99	WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
	100	superchan = NL80211_CHAN_HT40MINUS;
	101	break;
	102	}
	103	}
23a85b45	104	mutex_unlock(&local->iflist_mtx);
0aaffa9b	105
23a85b45 MK	106	return superchan;
	107	}
	108
	109	static bool
	110	ieee80211_channel_types_are_compatible(enum nl80211_channel_type chantype1,
	111	enum nl80211_channel_type chantype2,
	112	enum nl80211_channel_type *compat)
	113	{
	114	/*
	115	* start out with chantype1 being the result,
	116	* overwriting later if needed
	117	*/
	118	if (compat)
	119	*compat = chantype1;
	120
	121	switch (chantype1) {
0aaffa9b	122	case NL80211_CHAN_NO_HT:
23a85b45 MK	123	if (compat)
	124	*compat = chantype2;
	125	break;
0aaffa9b JB	126	case NL80211_CHAN_HT20:
	127	/*
	128	* allow any change that doesn't go to no-HT
	129	* (if it already is no-HT no change is needed)
	130	*/
23a85b45	131	if (chantype2 == NL80211_CHAN_NO_HT)
0aaffa9b	132	break;
23a85b45 MK	133	if (compat)
23a85b45 MK	134	*compat = chantype2;
0aaffa9b JB	135	break;
	136	case NL80211_CHAN_HT40PLUS:
	137	case NL80211_CHAN_HT40MINUS:
	138	/* allow smaller bandwidth and same */
23a85b45	139	if (chantype2 == NL80211_CHAN_NO_HT)
0aaffa9b	140	break;
23a85b45	141	if (chantype2 == NL80211_CHAN_HT20)
0aaffa9b	142	break;
23a85b45	143	if (chantype2 == chantype1)
0aaffa9b	144	break;
23a85b45	145	return false;
0aaffa9b JB	146	}
0aaffa9b JB	147
23a85b45 MK	148	return true;
	149	}
	150
	151	bool ieee80211_set_channel_type(struct ieee80211_local *local,
	152	struct ieee80211_sub_if_data *sdata,
	153	enum nl80211_channel_type chantype)
	154	{
	155	enum nl80211_channel_type superchan;
	156	enum nl80211_channel_type compatchan;
	157
	158	superchan = ieee80211_get_superchan(local, sdata);
	159	if (!ieee80211_channel_types_are_compatible(superchan, chantype,
	160	&compatchan))
	161	return false;
	162
	163	local->_oper_channel_type = compatchan;
0aaffa9b JB	164
	165	if (sdata)
	166	sdata->vif.bss_conf.channel_type = chantype;
	167
23a85b45	168	return true;
0aaffa9b	169
0aaffa9b	170	}