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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxxxx>
---
net/mac80211/ibss.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 4a10e00..2bd86a2 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -405,6 +405,61 @@ 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;
+}
+
+
/* must hold sdata lock */
int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
struct cfg80211_csa_settings *csa_settings)
@@ -458,6 +513,12 @@ 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;
--
1.7.10.4
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