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mac80211: send a CSA action frame when changing channel

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IBSS members may not immediately be able to send out their beacon when
performing CSA, therefore also send a CSA action frame.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Simon Wunderlich 2013-08-28 13:41:32 +02:00 committed by Johannes Berg
parent cd7760e62c
commit 9449410f3b
1 changed files with 60 additions and 0 deletions
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60
net/mac80211/ibss.c
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@ -428,6 +428,60 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
tsf, false);
}
static int ieee80211_send_action_csa(struct ieee80211_sub_if_data *sdata,
struct cfg80211_csa_settings *csa_settings)
{
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
int freq;
int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.chan_switch) +
sizeof(mgmt->u.action.u.chan_switch);
u8 *pos;
skb = dev_alloc_skb(local->tx_headroom + hdr_len +
5 + /* channel switch announcement element */
3); /* secondary channel offset element */
if (!skb)
return -1;
skb_reserve(skb, local->tx_headroom);
mgmt = (struct ieee80211_mgmt *)skb_put(skb, hdr_len);
memset(mgmt, 0, hdr_len);
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
eth_broadcast_addr(mgmt->da);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
mgmt->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
mgmt->u.action.u.chan_switch.action_code = WLAN_ACTION_SPCT_CHL_SWITCH;
pos = skb_put(skb, 5);
*pos++ = WLAN_EID_CHANNEL_SWITCH; /* EID */
*pos++ = 3; /* IE length */
*pos++ = csa_settings->block_tx ? 1 : 0; /* CSA mode */
freq = csa_settings->chandef.chan->center_freq;
*pos++ = ieee80211_frequency_to_channel(freq); /* channel */
*pos++ = csa_settings->count; /* count */
if (csa_settings->chandef.width == NL80211_CHAN_WIDTH_40) {
enum nl80211_channel_type ch_type;
skb_put(skb, 3);
*pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET; /* EID */
*pos++ = 1; /* IE length */
ch_type = cfg80211_get_chandef_type(&csa_settings->chandef);
if (ch_type == NL80211_CHAN_HT40PLUS)
*pos++ = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
else
*pos++ = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
}
ieee80211_tx_skb(sdata, skb);
return 0;
}
int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
struct cfg80211_csa_settings *csa_settings)
{
@ -480,6 +534,12 @@ int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
if (old_presp)
kfree_rcu(old_presp, rcu_head);
/* it might not send the beacon for a while. send an action frame
* immediately to announce the channel switch.
*/
if (csa_settings)
ieee80211_send_action_csa(sdata, csa_settings);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
out:
return ret;