chan.c 11.3 KB
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/*
 * mac80211 - channel management
 */

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#include <linux/nl80211.h>
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#include <linux/export.h>
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#include <linux/rtnetlink.h>
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#include <net/cfg80211.h>
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#include "ieee80211_i.h"
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#include "driver-ops.h"
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static void ieee80211_change_chanctx(struct ieee80211_local *local,
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				     struct ieee80211_chanctx *ctx,
				     const struct cfg80211_chan_def *chandef)
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{
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	if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
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		return;
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	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));

	ctx->conf.def = *chandef;
	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
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	if (!local->use_chanctx) {
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		local->_oper_channel_type = cfg80211_get_chandef_type(chandef);
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		ieee80211_hw_config(local, 0);
	}
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}
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static struct ieee80211_chanctx *
ieee80211_find_chanctx(struct ieee80211_local *local,
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		       const struct cfg80211_chan_def *chandef,
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		       enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_chanctx *ctx;

	lockdep_assert_held(&local->chanctx_mtx);

	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
		return NULL;

	list_for_each_entry(ctx, &local->chanctx_list, list) {
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		const struct cfg80211_chan_def *compat;
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		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
			continue;
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		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
		if (!compat)
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			continue;

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		ieee80211_change_chanctx(local, ctx, compat);
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		return ctx;
	}

	return NULL;
}

static struct ieee80211_chanctx *
ieee80211_new_chanctx(struct ieee80211_local *local,
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		      const struct cfg80211_chan_def *chandef,
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		      enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_chanctx *ctx;
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	int err;
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	lockdep_assert_held(&local->chanctx_mtx);

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

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	ctx->conf.def = *chandef;
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	ctx->conf.rx_chains_static = 1;
	ctx->conf.rx_chains_dynamic = 1;
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	ctx->mode = mode;

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	if (!local->use_chanctx) {
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		local->_oper_channel_type =
			cfg80211_get_chandef_type(chandef);
		local->_oper_channel = chandef->chan;
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		ieee80211_hw_config(local, 0);
	} else {
		err = drv_add_chanctx(local, ctx);
		if (err) {
			kfree(ctx);
			return ERR_PTR(err);
		}
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	}

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	list_add_rcu(&ctx->list, &local->chanctx_list);
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	mutex_lock(&local->mtx);
	ieee80211_recalc_idle(local);
	mutex_unlock(&local->mtx);

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	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);

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	if (!local->use_chanctx) {
		local->_oper_channel_type = NL80211_CHAN_NO_HT;
		ieee80211_hw_config(local, 0);
	} else {
		drv_remove_chanctx(local, ctx);
	}
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	list_del_rcu(&ctx->list);
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	kfree_rcu(ctx, rcu_head);
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	mutex_lock(&local->mtx);
	ieee80211_recalc_idle(local);
	mutex_unlock(&local->mtx);
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}

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

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

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

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	ieee80211_recalc_txpower(sdata);
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	sdata->vif.bss_conf.idle = false;
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	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
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	return 0;
}

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static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
					      struct ieee80211_chanctx *ctx)
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{
	struct ieee80211_chanctx_conf *conf = &ctx->conf;
	struct ieee80211_sub_if_data *sdata;
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	const struct cfg80211_chan_def *compat = NULL;
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	lockdep_assert_held(&local->chanctx_mtx);

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

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		if (!compat)
			compat = &sdata->vif.bss_conf.chandef;

		compat = cfg80211_chandef_compatible(
				&sdata->vif.bss_conf.chandef, compat);
		if (!compat)
			break;
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	}
	rcu_read_unlock();

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	if (WARN_ON_ONCE(!compat))
		return;
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	ieee80211_change_chanctx(local, ctx, compat);
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}

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

	ctx->refcount--;
	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
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	sdata->vif.bss_conf.idle = true;
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	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
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	drv_unassign_vif_chanctx(local, sdata, ctx);
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	if (ctx->refcount > 0) {
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		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
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		ieee80211_recalc_smps_chanctx(local, ctx);
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		ieee80211_recalc_radar_chanctx(local, ctx);
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	}
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}

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);
}

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void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
				    struct ieee80211_chanctx *chanctx)
{
	struct ieee80211_sub_if_data *sdata;
	bool radar_enabled = false;

	lockdep_assert_held(&local->chanctx_mtx);

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		if (sdata->radar_required) {
			radar_enabled = true;
			break;
		}
	}
	rcu_read_unlock();

	if (radar_enabled == chanctx->conf.radar_enabled)
		return;

	chanctx->conf.radar_enabled = radar_enabled;
	local->radar_detect_enabled = chanctx->conf.radar_enabled;

	if (!local->use_chanctx) {
		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	}

	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
}

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void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
				   struct ieee80211_chanctx *chanctx)
{
	struct ieee80211_sub_if_data *sdata;
	u8 rx_chains_static, rx_chains_dynamic;

	lockdep_assert_held(&local->chanctx_mtx);

	rx_chains_static = 1;
	rx_chains_dynamic = 1;

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		u8 needed_static, needed_dynamic;

		if (!ieee80211_sdata_running(sdata))
			continue;

		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
						&chanctx->conf)
			continue;

		switch (sdata->vif.type) {
		case NL80211_IFTYPE_P2P_DEVICE:
			continue;
		case NL80211_IFTYPE_STATION:
			if (!sdata->u.mgd.associated)
				continue;
			break;
		case NL80211_IFTYPE_AP_VLAN:
			continue;
		case NL80211_IFTYPE_AP:
		case NL80211_IFTYPE_ADHOC:
		case NL80211_IFTYPE_WDS:
		case NL80211_IFTYPE_MESH_POINT:
			break;
		default:
			WARN_ON_ONCE(1);
		}

		switch (sdata->smps_mode) {
		default:
			WARN_ONCE(1, "Invalid SMPS mode %d\n",
				  sdata->smps_mode);
			/* fall through */
		case IEEE80211_SMPS_OFF:
			needed_static = sdata->needed_rx_chains;
			needed_dynamic = sdata->needed_rx_chains;
			break;
		case IEEE80211_SMPS_DYNAMIC:
			needed_static = 1;
			needed_dynamic = sdata->needed_rx_chains;
			break;
		case IEEE80211_SMPS_STATIC:
			needed_static = 1;
			needed_dynamic = 1;
			break;
		}

		rx_chains_static = max(rx_chains_static, needed_static);
		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
	}
	rcu_read_unlock();

	if (!local->use_chanctx) {
		if (rx_chains_static > 1)
			local->smps_mode = IEEE80211_SMPS_OFF;
		else if (rx_chains_dynamic > 1)
			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
		else
			local->smps_mode = IEEE80211_SMPS_STATIC;
		ieee80211_hw_config(local, 0);
	}

	if (rx_chains_static == chanctx->conf.rx_chains_static &&
	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
		return;

	chanctx->conf.rx_chains_static = rx_chains_static;
	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
}

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int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
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			      const struct cfg80211_chan_def *chandef,
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			      enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx *ctx;
	int ret;

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

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

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

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	sdata->vif.bss_conf.chandef = *chandef;
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	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;
	}

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	ieee80211_recalc_smps_chanctx(local, ctx);
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	ieee80211_recalc_radar_chanctx(local, ctx);
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 out:
	mutex_unlock(&local->chanctx_mtx);
	return ret;
}

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

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	mutex_lock(&sdata->local->chanctx_mtx);
	__ieee80211_vif_release_channel(sdata);
	mutex_unlock(&sdata->local->chanctx_mtx);
}
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void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_sub_if_data *ap;
	struct ieee80211_chanctx_conf *conf;

	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
		return;

	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);

	mutex_lock(&local->chanctx_mtx);

	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
					 lockdep_is_held(&local->chanctx_mtx));
	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
	mutex_unlock(&local->chanctx_mtx);
}

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void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
					 bool clear)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_sub_if_data *vlan;
	struct ieee80211_chanctx_conf *conf;

	ASSERT_RTNL();

	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
		return;

	mutex_lock(&local->chanctx_mtx);

	/*
	 * Check that conf exists, even when clearing this function
	 * must be called with the AP's channel context still there
	 * as it would otherwise cause VLANs to have an invalid
	 * channel context pointer for a while, possibly pointing
	 * to a channel context that has already been freed.
	 */
	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
				lockdep_is_held(&local->chanctx_mtx));
	WARN_ON(!conf);

	if (clear)
		conf = NULL;

	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);

	mutex_unlock(&local->chanctx_mtx);
}

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void ieee80211_iter_chan_contexts_atomic(
	struct ieee80211_hw *hw,
	void (*iter)(struct ieee80211_hw *hw,
		     struct ieee80211_chanctx_conf *chanctx_conf,
		     void *data),
	void *iter_data)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_chanctx *ctx;

	rcu_read_lock();
	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
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		if (ctx->driver_present)
			iter(hw, &ctx->conf, iter_data);
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	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);