103 lines
2.4 KiB
C
103 lines
2.4 KiB
C
/*
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* This file contains helper code to handle channel
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* settings and keeping track of what is possible at
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* any point in time.
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*
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* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
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*/
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#include <net/cfg80211.h>
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#include "core.h"
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struct ieee80211_channel *
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rdev_fixed_channel(struct cfg80211_registered_device *rdev,
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struct wireless_dev *for_wdev)
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{
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struct wireless_dev *wdev;
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struct ieee80211_channel *result = NULL;
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WARN_ON(!mutex_is_locked(&rdev->devlist_mtx));
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list_for_each_entry(wdev, &rdev->netdev_list, list) {
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if (wdev == for_wdev)
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continue;
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/*
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* Lock manually to tell lockdep about allowed
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* nesting here if for_wdev->mtx is held already.
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* This is ok as it's all under the rdev devlist
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* mutex and as such can only be done once at any
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* given time.
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*/
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mutex_lock_nested(&wdev->mtx, SINGLE_DEPTH_NESTING);
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if (wdev->current_bss)
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result = wdev->current_bss->pub.channel;
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wdev_unlock(wdev);
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if (result)
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break;
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}
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return result;
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}
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struct ieee80211_channel *
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rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
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int freq, enum nl80211_channel_type channel_type)
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{
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struct ieee80211_channel *chan;
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struct ieee80211_sta_ht_cap *ht_cap;
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chan = ieee80211_get_channel(&rdev->wiphy, freq);
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/* Primary channel not allowed */
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if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
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return NULL;
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if (channel_type == NL80211_CHAN_HT40MINUS &&
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chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
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return NULL;
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else if (channel_type == NL80211_CHAN_HT40PLUS &&
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chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
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return NULL;
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ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
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if (channel_type != NL80211_CHAN_NO_HT) {
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if (!ht_cap->ht_supported)
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return NULL;
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if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
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ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
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return NULL;
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}
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return chan;
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}
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int rdev_set_freq(struct cfg80211_registered_device *rdev,
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struct wireless_dev *for_wdev,
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int freq, enum nl80211_channel_type channel_type)
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{
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struct ieee80211_channel *chan;
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int result;
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if (rdev_fixed_channel(rdev, for_wdev))
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return -EBUSY;
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if (!rdev->ops->set_channel)
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return -EOPNOTSUPP;
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chan = rdev_freq_to_chan(rdev, freq, channel_type);
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if (!chan)
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return -EINVAL;
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result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
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if (result)
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return result;
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rdev->channel = chan;
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return 0;
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}
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