linux/net/wireless/chan.c
Johannes Berg 4290cb4bf2 cfg80211: reduce monitor interface tracking
Revert commit b78e8ceac2
("cfg80211: track monitor channel") and remove the
set_monitor_enabled() callback.

Due to the tracking happening in NETDEV_PRE_UP, it had
introduced bugs because the monitor interface callback
would be called before the device was started. It looks
like there's no way to fix this, and using NETDEV_PRE_UP
is broken anyway (since there's no NETDEV_UP_FAIL), so
remove all that code, track interfaces in NETDEV_UP and
also stop tracking the monitor channel in cfg80211.

This mostly reverts to before the tracking, except that
we keep the interface count tracking so that setting the
monitor channel can be rejected properly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-07-13 16:16:11 +02:00

152 lines
3.5 KiB
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;
if (!cfg80211_has_monitors_only(rdev))
return -EBUSY;
chan = rdev_freq_to_chan(rdev, freq, chantype);
if (!chan)
return -EINVAL;
return rdev->ops->set_monitor_channel(&rdev->wiphy, chan, chantype);
}
void
cfg80211_get_chan_state(struct wireless_dev *wdev,
struct ieee80211_channel **chan,
enum cfg80211_chan_mode *chanmode)
{
*chan = NULL;
*chanmode = CHAN_MODE_UNDEFINED;
ASSERT_WDEV_LOCK(wdev);
if (!netif_running(wdev->netdev))
return;
switch (wdev->iftype) {
case NL80211_IFTYPE_ADHOC:
if (wdev->current_bss) {
*chan = wdev->current_bss->pub.channel;
*chanmode = wdev->ibss_fixed
? CHAN_MODE_SHARED
: CHAN_MODE_EXCLUSIVE;
return;
}
case NL80211_IFTYPE_STATION:
case NL80211_IFTYPE_P2P_CLIENT:
if (wdev->current_bss) {
*chan = wdev->current_bss->pub.channel;
*chanmode = CHAN_MODE_SHARED;
return;
}
break;
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_P2P_GO:
if (wdev->beacon_interval) {
*chan = wdev->channel;
*chanmode = CHAN_MODE_SHARED;
}
return;
case NL80211_IFTYPE_MESH_POINT:
if (wdev->mesh_id_len) {
*chan = wdev->channel;
*chanmode = CHAN_MODE_SHARED;
}
return;
case NL80211_IFTYPE_MONITOR:
case NL80211_IFTYPE_AP_VLAN:
case NL80211_IFTYPE_WDS:
/* these interface types don't really have a channel */
return;
case NL80211_IFTYPE_UNSPECIFIED:
case NUM_NL80211_IFTYPES:
WARN_ON(1);
}
return;
}