From: Simon Wunderlich Date: Wed, 28 Aug 2013 11:41:32 +0000 (+0200) Subject: mac80211: send a CSA action frame when changing channel X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9449410f3b30a27824aa02adec485e18b740b756;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git mac80211: send a CSA action frame when changing channel 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 Signed-off-by: Mathias Kretschmer Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c index c0042136f1d8..5ea9b3ae303e 100644 --- a/net/mac80211/ibss.c +++ b/net/mac80211/ibss.c @@ -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;