/* * 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; } int 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 false; } 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_freq(struct cfg80211_registered_device *rdev, struct wireless_dev *wdev, int freq, enum nl80211_channel_type channel_type) { struct ieee80211_channel *chan; int result; if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR) wdev = NULL; if (wdev) { ASSERT_WDEV_LOCK(wdev); if (!netif_running(wdev->netdev)) return -ENETDOWN; } if (!rdev->ops->set_channel) return -EOPNOTSUPP; chan = rdev_freq_to_chan(rdev, freq, channel_type); if (!chan) return -EINVAL; /* Both channels should be able to initiate communication */ if (wdev && (wdev->iftype == NL80211_IFTYPE_ADHOC || wdev->iftype == NL80211_IFTYPE_AP || wdev->iftype == NL80211_IFTYPE_AP_VLAN || wdev->iftype == NL80211_IFTYPE_MESH_POINT || wdev->iftype == NL80211_IFTYPE_P2P_GO)) { switch (channel_type) { case NL80211_CHAN_HT40PLUS: case NL80211_CHAN_HT40MINUS: if (!cfg80211_can_beacon_sec_chan(&rdev->wiphy, chan, channel_type)) { printk(KERN_DEBUG "cfg80211: Secondary channel not " "allowed to initiate communication\n"); return -EINVAL; } break; default: break; } } result = rdev->ops->set_channel(&rdev->wiphy, wdev ? wdev->netdev : NULL, chan, channel_type); if (result) return result; if (wdev) wdev->channel = chan; return 0; }