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linux/net/mac80211/chan.c
Simon Wunderlich 73da7d5bab mac80211: add channel switch command and beacon callbacks 
The count field in CSA must be decremented with each beacon
transmitted. This patch implements the functionality for drivers
using ieee80211_beacon_get(). Other drivers must call back manually
after reaching count == 0.

This patch also contains the handling and finish worker for the channel
switch command, and mac80211/chanctx code to allow to change a channel
definition of an active channel context.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[small cleanups, catch identical chandef]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-08-01 18:30:33 +02:00

599 lines
15 KiB
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/*
* mac80211 - channel management
*/
#include <linux/nl80211.h>
#include <linux/export.h>
#include <linux/rtnetlink.h>
#include <net/cfg80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
static void ieee80211_change_chanctx(struct ieee80211_local *local,
struct ieee80211_chanctx *ctx,
const struct cfg80211_chan_def *chandef)
{
if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
return;
WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
ctx->conf.def = *chandef;
drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
if (!local->use_chanctx) {
local->_oper_chandef = *chandef;
ieee80211_hw_config(local, 0);
}
}
static struct ieee80211_chanctx *
ieee80211_find_chanctx(struct ieee80211_local *local,
const struct cfg80211_chan_def *chandef,
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) {
const struct cfg80211_chan_def *compat;
if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
continue;
compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
if (!compat)
continue;
ieee80211_change_chanctx(local, ctx, compat);
return ctx;
}
return NULL;
}
static bool ieee80211_is_radar_required(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;
rcu_read_lock();
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (sdata->radar_required) {
rcu_read_unlock();
return true;
}
}
rcu_read_unlock();
return false;
}
static struct ieee80211_chanctx *
ieee80211_new_chanctx(struct ieee80211_local *local,
const struct cfg80211_chan_def *chandef,
enum ieee80211_chanctx_mode mode)
{
struct ieee80211_chanctx *ctx;
u32 changed;
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.def = *chandef;
ctx->conf.rx_chains_static = 1;
ctx->conf.rx_chains_dynamic = 1;
ctx->mode = mode;
ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
if (!local->use_chanctx)
local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
/* acquire mutex to prevent idle from changing */
mutex_lock(&local->mtx);
/* turn idle off *before* setting channel -- some drivers need that */
changed = ieee80211_idle_off(local);
if (changed)
ieee80211_hw_config(local, changed);
if (!local->use_chanctx) {
local->_oper_chandef = *chandef;
ieee80211_hw_config(local, 0);
} else {
err = drv_add_chanctx(local, ctx);
if (err) {
kfree(ctx);
ctx = ERR_PTR(err);
ieee80211_recalc_idle(local);
goto out;
}
}
/* and keep the mutex held until the new chanctx is on the list */
list_add_rcu(&ctx->list, &local->chanctx_list);
out:
mutex_unlock(&local->mtx);
return ctx;
}
static void ieee80211_free_chanctx(struct ieee80211_local *local,
struct ieee80211_chanctx *ctx)
{
bool check_single_channel = false;
lockdep_assert_held(&local->chanctx_mtx);
WARN_ON_ONCE(ctx->refcount != 0);
if (!local->use_chanctx) {
struct cfg80211_chan_def *chandef = &local->_oper_chandef;
chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
chandef->center_freq1 = chandef->chan->center_freq;
chandef->center_freq2 = 0;
/* NOTE: Disabling radar is only valid here for
* single channel context. To be sure, check it ...
*/
if (local->hw.conf.radar_enabled)
check_single_channel = true;
local->hw.conf.radar_enabled = false;
ieee80211_hw_config(local, 0);
} else {
drv_remove_chanctx(local, ctx);
}
list_del_rcu(&ctx->list);
kfree_rcu(ctx, rcu_head);
/* throw a warning if this wasn't the only channel context. */
WARN_ON(check_single_channel && !list_empty(&local->chanctx_list));
mutex_lock(&local->mtx);
ieee80211_recalc_idle(local);
mutex_unlock(&local->mtx);
}
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++;
ieee80211_recalc_txpower(sdata);
sdata->vif.bss_conf.idle = false;
if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
sdata->vif.type != NL80211_IFTYPE_MONITOR)
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
return 0;
}
static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
struct ieee80211_chanctx *ctx)
{
struct ieee80211_chanctx_conf *conf = &ctx->conf;
struct ieee80211_sub_if_data *sdata;
const struct cfg80211_chan_def *compat = NULL;
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;
if (!compat)
compat = &sdata->vif.bss_conf.chandef;
compat = cfg80211_chandef_compatible(
&sdata->vif.bss_conf.chandef, compat);
if (!compat)
break;
}
rcu_read_unlock();
if (WARN_ON_ONCE(!compat))
return;
ieee80211_change_chanctx(local, ctx, compat);
}
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);
sdata->vif.bss_conf.idle = true;
if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
sdata->vif.type != NL80211_IFTYPE_MONITOR)
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
drv_unassign_vif_chanctx(local, sdata, ctx);
if (ctx->refcount > 0) {
ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
ieee80211_recalc_smps_chanctx(local, ctx);
ieee80211_recalc_radar_chanctx(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);
}
void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
struct ieee80211_chanctx *chanctx)
{
bool radar_enabled;
lockdep_assert_held(&local->chanctx_mtx);
radar_enabled = ieee80211_is_radar_required(local);
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);
}
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);
}
int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
const struct cfg80211_chan_def *chandef,
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, chandef, mode);
if (!ctx)
ctx = ieee80211_new_chanctx(local, chandef, mode);
if (IS_ERR(ctx)) {
ret = PTR_ERR(ctx);
goto out;
}
sdata->vif.bss_conf.chandef = *chandef;
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;
}
ieee80211_recalc_smps_chanctx(local, ctx);
ieee80211_recalc_radar_chanctx(local, ctx);
out:
mutex_unlock(&local->chanctx_mtx);
return ret;
}
int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
const struct cfg80211_chan_def *chandef,
u32 *changed)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_chanctx_conf *conf;
struct ieee80211_chanctx *ctx;
int ret;
u32 chanctx_changed = 0;
/* should never be called if not performing a channel switch. */
if (WARN_ON(!sdata->vif.csa_active))
return -EINVAL;
if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
IEEE80211_CHAN_DISABLED))
return -EINVAL;
mutex_lock(&local->chanctx_mtx);
conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
lockdep_is_held(&local->chanctx_mtx));
if (!conf) {
ret = -EINVAL;
goto out;
}
ctx = container_of(conf, struct ieee80211_chanctx, conf);
if (ctx->refcount != 1) {
ret = -EINVAL;
goto out;
}
if (sdata->vif.bss_conf.chandef.width != chandef->width) {
chanctx_changed = IEEE80211_CHANCTX_CHANGE_WIDTH;
*changed |= BSS_CHANGED_BANDWIDTH;
}
sdata->vif.bss_conf.chandef = *chandef;
ctx->conf.def = *chandef;
chanctx_changed |= IEEE80211_CHANCTX_CHANGE_CHANNEL;
drv_change_chanctx(local, ctx, chanctx_changed);
if (!local->use_chanctx) {
local->_oper_chandef = *chandef;
ieee80211_hw_config(local, 0);
}
ieee80211_recalc_chanctx_chantype(local, ctx);
ieee80211_recalc_smps_chanctx(local, ctx);
ieee80211_recalc_radar_chanctx(local, ctx);
ret = 0;
out:
mutex_unlock(&local->chanctx_mtx);
return ret;
}
int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
const struct cfg80211_chan_def *chandef,
u32 *changed)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_chanctx_conf *conf;
struct ieee80211_chanctx *ctx;
int ret;
if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
IEEE80211_CHAN_DISABLED))
return -EINVAL;
mutex_lock(&local->chanctx_mtx);
if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
ret = 0;
goto out;
}
if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
ret = -EINVAL;
goto out;
}
conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
lockdep_is_held(&local->chanctx_mtx));
if (!conf) {
ret = -EINVAL;
goto out;
}
ctx = container_of(conf, struct ieee80211_chanctx, conf);
if (!cfg80211_chandef_compatible(&conf->def, chandef)) {
ret = -EINVAL;
goto out;
}
sdata->vif.bss_conf.chandef = *chandef;
ieee80211_recalc_chanctx_chantype(local, ctx);
*changed |= BSS_CHANGED_BANDWIDTH;
ret = 0;
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);
}
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);
}
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);
}
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)
if (ctx->driver_present)
iter(hw, &ctx->conf, iter_data);
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
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