[mirror_ubuntu-jammy-kernel.git] / net / mac80211 / chan.c

/*
 * mac80211 - channel management
 */

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

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;
}

static void ieee80211_change_chantype(struct ieee80211_local *local,
				      struct ieee80211_chanctx *ctx,
				      enum nl80211_channel_type chantype)
{
	if (chantype == ctx->conf.channel_type)
		return;

	ctx->conf.channel_type = chantype;
	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE);

	if (!local->use_chanctx) {
		local->_oper_channel_type = chantype;
		ieee80211_hw_config(local, 0);
	}
}

static struct ieee80211_chanctx *
ieee80211_find_chanctx(struct ieee80211_local *local,
		       struct ieee80211_channel *channel,
		       enum nl80211_channel_type channel_type,
		       enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_chanctx *ctx;
	enum nl80211_channel_type compat_type;

	lockdep_assert_held(&local->chanctx_mtx);

	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
		return NULL;
	if (WARN_ON(!channel))
		return NULL;

	list_for_each_entry(ctx, &local->chanctx_list, list) {
		compat_type = ctx->conf.channel_type;

		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
			continue;
		if (ctx->conf.channel != channel)
			continue;
		if (!ieee80211_channel_types_are_compatible(ctx->conf.channel_type,
							    channel_type,
							    &compat_type))
			continue;

		ieee80211_change_chantype(local, ctx, compat_type);

		return ctx;
	}

	return NULL;
}

static struct ieee80211_chanctx *
ieee80211_new_chanctx(struct ieee80211_local *local,
		      struct ieee80211_channel *channel,
		      enum nl80211_channel_type channel_type,
		      enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_chanctx *ctx;
	int err;

	lockdep_assert_held(&local->chanctx_mtx);

	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
	if (!ctx)
		return ERR_PTR(-ENOMEM);

	ctx->conf.channel = channel;
	ctx->conf.channel_type = channel_type;
	ctx->mode = mode;

	if (!local->use_chanctx) {
		local->_oper_channel_type = channel_type;
		local->_oper_channel = channel;
		ieee80211_hw_config(local, 0);
	} else {
		err = drv_add_chanctx(local, ctx);
		if (err) {
			kfree(ctx);
			return ERR_PTR(err);
		}
	}

	list_add(&ctx->list, &local->chanctx_list);

	return ctx;
}

static void ieee80211_free_chanctx(struct ieee80211_local *local,
				   struct ieee80211_chanctx *ctx)
{
	lockdep_assert_held(&local->chanctx_mtx);

	WARN_ON_ONCE(ctx->refcount != 0);

	if (!local->use_chanctx) {
		local->_oper_channel_type = NL80211_CHAN_NO_HT;
		ieee80211_hw_config(local, 0);
	} else {
		drv_remove_chanctx(local, ctx);
	}

	list_del(&ctx->list);
	kfree_rcu(ctx, rcu_head);
}

static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_chanctx *ctx)
{
	struct ieee80211_local *local = sdata->local;
	int ret;

	lockdep_assert_held(&local->chanctx_mtx);

	ret = drv_assign_vif_chanctx(local, sdata, ctx);
	if (ret)
		return ret;

	rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
	ctx->refcount++;

	return 0;
}

static enum nl80211_channel_type
ieee80211_calc_chantype(struct ieee80211_local *local,
			struct ieee80211_chanctx *ctx)
{
	struct ieee80211_chanctx_conf *conf = &ctx->conf;
	struct ieee80211_sub_if_data *sdata;
	enum nl80211_channel_type result = NL80211_CHAN_NO_HT;

	lockdep_assert_held(&local->chanctx_mtx);

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		if (!ieee80211_sdata_running(sdata))
			continue;
		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
			continue;

		WARN_ON_ONCE(!ieee80211_channel_types_are_compatible(
					sdata->vif.bss_conf.channel_type,
					result, &result));
	}
	rcu_read_unlock();

	return result;
}

static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
					      struct ieee80211_chanctx *ctx)
{
	enum nl80211_channel_type chantype;

	lockdep_assert_held(&local->chanctx_mtx);

	chantype = ieee80211_calc_chantype(local, ctx);
	ieee80211_change_chantype(local, ctx, chantype);
}

static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
					   struct ieee80211_chanctx *ctx)
{
	struct ieee80211_local *local = sdata->local;

	lockdep_assert_held(&local->chanctx_mtx);

	ctx->refcount--;
	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);

	drv_unassign_vif_chanctx(local, sdata, ctx);

	if (ctx->refcount > 0)
		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
}

static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx_conf *conf;
	struct ieee80211_chanctx *ctx;

	lockdep_assert_held(&local->chanctx_mtx);

	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
					 lockdep_is_held(&local->chanctx_mtx));
	if (!conf)
		return;

	ctx = container_of(conf, struct ieee80211_chanctx, conf);

	ieee80211_unassign_vif_chanctx(sdata, ctx);
	if (ctx->refcount == 0)
		ieee80211_free_chanctx(local, ctx);
}

int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
			      struct ieee80211_channel *channel,
			      enum nl80211_channel_type channel_type,
			      enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx *ctx;
	int ret;

	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));

	mutex_lock(&local->chanctx_mtx);
	__ieee80211_vif_release_channel(sdata);

	ctx = ieee80211_find_chanctx(local, channel, channel_type, mode);
	if (!ctx)
		ctx = ieee80211_new_chanctx(local, channel, channel_type, mode);
	if (IS_ERR(ctx)) {
		ret = PTR_ERR(ctx);
		goto out;
	}

	sdata->vif.bss_conf.channel_type = channel_type;

	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
	if (ret) {
		/* if assign fails refcount stays the same */
		if (ctx->refcount == 0)
			ieee80211_free_chanctx(local, ctx);
		goto out;
	}

 out:
	mutex_unlock(&local->chanctx_mtx);
	return ret;
}

void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
{
	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));

	mutex_lock(&sdata->local->chanctx_mtx);
	__ieee80211_vif_release_channel(sdata);
	mutex_unlock(&sdata->local->chanctx_mtx);
}
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	7	#include "ieee80211_i.h"
35f2fce9	8	#include "driver-ops.h"
f444de05	9
23a85b45 MK	10	static bool
	11	ieee80211_channel_types_are_compatible(enum nl80211_channel_type chantype1,
	12	enum nl80211_channel_type chantype2,
	13	enum nl80211_channel_type *compat)
	14	{
	15	/*
	16	* start out with chantype1 being the result,
	17	* overwriting later if needed
	18	*/
	19	if (compat)
	20	*compat = chantype1;
	21
	22	switch (chantype1) {
0aaffa9b	23	case NL80211_CHAN_NO_HT:
23a85b45 MK	24	if (compat)
	25	*compat = chantype2;
	26	break;
0aaffa9b JB	27	case NL80211_CHAN_HT20:
	28	/*
	29	* allow any change that doesn't go to no-HT
	30	* (if it already is no-HT no change is needed)
	31	*/
23a85b45	32	if (chantype2 == NL80211_CHAN_NO_HT)
0aaffa9b	33	break;
23a85b45 MK	34	if (compat)
23a85b45 MK	35	*compat = chantype2;
0aaffa9b JB	36	break;
	37	case NL80211_CHAN_HT40PLUS:
	38	case NL80211_CHAN_HT40MINUS:
	39	/* allow smaller bandwidth and same */
23a85b45	40	if (chantype2 == NL80211_CHAN_NO_HT)
0aaffa9b	41	break;
23a85b45	42	if (chantype2 == NL80211_CHAN_HT20)
0aaffa9b	43	break;
23a85b45	44	if (chantype2 == chantype1)
0aaffa9b	45	break;
23a85b45	46	return false;
0aaffa9b JB	47	}
0aaffa9b JB	48
23a85b45 MK	49	return true;
	50	}
	51
e89a96f5 MK	52	static void ieee80211_change_chantype(struct ieee80211_local *local,
	53	struct ieee80211_chanctx *ctx,
	54	enum nl80211_channel_type chantype)
	55	{
	56	if (chantype == ctx->conf.channel_type)
	57	return;
0aaffa9b	58
e89a96f5 MK	59	ctx->conf.channel_type = chantype;
e89a96f5 MK	60	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE);
55de908a JB	61
	62	if (!local->use_chanctx) {
	63	local->_oper_channel_type = chantype;
	64	ieee80211_hw_config(local, 0);
	65	}
0aaffa9b	66	}
d01a1e65 MK	67
	68	static struct ieee80211_chanctx *
	69	ieee80211_find_chanctx(struct ieee80211_local *local,
	70	struct ieee80211_channel *channel,
	71	enum nl80211_channel_type channel_type,
	72	enum ieee80211_chanctx_mode mode)
	73	{
	74	struct ieee80211_chanctx *ctx;
e89a96f5	75	enum nl80211_channel_type compat_type;
d01a1e65 MK	76
	77	lockdep_assert_held(&local->chanctx_mtx);
	78
	79	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
	80	return NULL;
	81	if (WARN_ON(!channel))
	82	return NULL;
	83
	84	list_for_each_entry(ctx, &local->chanctx_list, list) {
e89a96f5 MK	85	compat_type = ctx->conf.channel_type;
e89a96f5 MK	86
d01a1e65 MK	87	if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
	88	continue;
	89	if (ctx->conf.channel != channel)
	90	continue;
e89a96f5 MK	91	if (!ieee80211_channel_types_are_compatible(ctx->conf.channel_type,
	92	channel_type,
	93	&compat_type))
d01a1e65 MK	94	continue;
d01a1e65 MK	95
e89a96f5 MK	96	ieee80211_change_chantype(local, ctx, compat_type);
e89a96f5 MK	97
d01a1e65 MK	98	return ctx;
	99	}
	100
	101	return NULL;
	102	}
	103
	104	static struct ieee80211_chanctx *
	105	ieee80211_new_chanctx(struct ieee80211_local *local,
	106	struct ieee80211_channel *channel,
	107	enum nl80211_channel_type channel_type,
	108	enum ieee80211_chanctx_mode mode)
	109	{
	110	struct ieee80211_chanctx *ctx;
35f2fce9	111	int err;
d01a1e65 MK	112
	113	lockdep_assert_held(&local->chanctx_mtx);
	114
	115	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
	116	if (!ctx)
	117	return ERR_PTR(-ENOMEM);
	118
	119	ctx->conf.channel = channel;
	120	ctx->conf.channel_type = channel_type;
	121	ctx->mode = mode;
	122
55de908a JB	123	if (!local->use_chanctx) {
	124	local->_oper_channel_type = channel_type;
	125	local->_oper_channel = channel;
	126	ieee80211_hw_config(local, 0);
	127	} else {
	128	err = drv_add_chanctx(local, ctx);
	129	if (err) {
	130	kfree(ctx);
	131	return ERR_PTR(err);
	132	}
35f2fce9 MK	133	}
35f2fce9 MK	134
d01a1e65 MK	135	list_add(&ctx->list, &local->chanctx_list);
	136
	137	return ctx;
	138	}
	139
	140	static void ieee80211_free_chanctx(struct ieee80211_local *local,
	141	struct ieee80211_chanctx *ctx)
	142	{
	143	lockdep_assert_held(&local->chanctx_mtx);
	144
	145	WARN_ON_ONCE(ctx->refcount != 0);
	146
55de908a JB	147	if (!local->use_chanctx) {
	148	local->_oper_channel_type = NL80211_CHAN_NO_HT;
	149	ieee80211_hw_config(local, 0);
	150	} else {
	151	drv_remove_chanctx(local, ctx);
	152	}
35f2fce9	153
d01a1e65 MK	154	list_del(&ctx->list);
	155	kfree_rcu(ctx, rcu_head);
	156	}
	157
	158	static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
	159	struct ieee80211_chanctx *ctx)
	160	{
35f2fce9 MK	161	struct ieee80211_local *local = sdata->local;
35f2fce9 MK	162	int ret;
d01a1e65 MK	163
	164	lockdep_assert_held(&local->chanctx_mtx);
	165
35f2fce9 MK	166	ret = drv_assign_vif_chanctx(local, sdata, ctx);
	167	if (ret)
	168	return ret;
	169
d01a1e65 MK	170	rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
	171	ctx->refcount++;
	172
	173	return 0;
	174	}
	175
e89a96f5 MK	176	static enum nl80211_channel_type
	177	ieee80211_calc_chantype(struct ieee80211_local *local,
	178	struct ieee80211_chanctx *ctx)
	179	{
	180	struct ieee80211_chanctx_conf *conf = &ctx->conf;
	181	struct ieee80211_sub_if_data *sdata;
	182	enum nl80211_channel_type result = NL80211_CHAN_NO_HT;
	183
	184	lockdep_assert_held(&local->chanctx_mtx);
	185
	186	rcu_read_lock();
	187	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
	188	if (!ieee80211_sdata_running(sdata))
	189	continue;
	190	if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
	191	continue;
	192
	193	WARN_ON_ONCE(!ieee80211_channel_types_are_compatible(
	194	sdata->vif.bss_conf.channel_type,
	195	result, &result));
	196	}
	197	rcu_read_unlock();
	198
	199	return result;
	200	}
	201
	202	static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
	203	struct ieee80211_chanctx *ctx)
	204	{
	205	enum nl80211_channel_type chantype;
	206
	207	lockdep_assert_held(&local->chanctx_mtx);
	208
	209	chantype = ieee80211_calc_chantype(local, ctx);
	210	ieee80211_change_chantype(local, ctx, chantype);
	211	}
	212
d01a1e65 MK	213	static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
	214	struct ieee80211_chanctx *ctx)
	215	{
35f2fce9	216	struct ieee80211_local *local = sdata->local;
d01a1e65 MK	217
	218	lockdep_assert_held(&local->chanctx_mtx);
	219
	220	ctx->refcount--;
	221	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
35f2fce9 MK	222
35f2fce9 MK	223	drv_unassign_vif_chanctx(local, sdata, ctx);
e89a96f5 MK	224
	225	if (ctx->refcount > 0)
	226	ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
d01a1e65 MK	227	}
	228
	229	static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
	230	{
	231	struct ieee80211_local *local = sdata->local;
	232	struct ieee80211_chanctx_conf *conf;
	233	struct ieee80211_chanctx *ctx;
	234
	235	lockdep_assert_held(&local->chanctx_mtx);
	236
	237	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
	238	lockdep_is_held(&local->chanctx_mtx));
	239	if (!conf)
	240	return;
	241
	242	ctx = container_of(conf, struct ieee80211_chanctx, conf);
	243
	244	ieee80211_unassign_vif_chanctx(sdata, ctx);
	245	if (ctx->refcount == 0)
	246	ieee80211_free_chanctx(local, ctx);
	247	}
	248
	249	int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
	250	struct ieee80211_channel *channel,
	251	enum nl80211_channel_type channel_type,
	252	enum ieee80211_chanctx_mode mode)
	253	{
	254	struct ieee80211_local *local = sdata->local;
	255	struct ieee80211_chanctx *ctx;
	256	int ret;
	257
55de908a JB	258	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
55de908a JB	259
d01a1e65 MK	260	mutex_lock(&local->chanctx_mtx);
	261	__ieee80211_vif_release_channel(sdata);
	262
	263	ctx = ieee80211_find_chanctx(local, channel, channel_type, mode);
	264	if (!ctx)
	265	ctx = ieee80211_new_chanctx(local, channel, channel_type, mode);
	266	if (IS_ERR(ctx)) {
	267	ret = PTR_ERR(ctx);
	268	goto out;
	269	}
	270
55de908a JB	271	sdata->vif.bss_conf.channel_type = channel_type;
55de908a JB	272
d01a1e65 MK	273	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
	274	if (ret) {
	275	/* if assign fails refcount stays the same */
	276	if (ctx->refcount == 0)
	277	ieee80211_free_chanctx(local, ctx);
	278	goto out;
	279	}
	280
	281	out:
	282	mutex_unlock(&local->chanctx_mtx);
	283	return ret;
	284	}
	285
	286	void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
	287	{
55de908a JB	288	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
55de908a JB	289
d01a1e65 MK	290	mutex_lock(&sdata->local->chanctx_mtx);
	291	__ieee80211_vif_release_channel(sdata);
	292	mutex_unlock(&sdata->local->chanctx_mtx);
	293	}