{nl,cfg,mac}80211: enable the triggering of CSA frame in mesh

Allow the triggering of CSA frame using mesh interface. The
rules are more or less same with IBSS, such as not allowed to
change between the band and channel width has to be same from
the previous mode. Also, move the ieee80211_send_action_csa
to a common space so that it can be re-used by mesh interface.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 523783cedf6e..a38d58231af8 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2384,3 +2384,90 @@ bool ieee80211_smps_is_restrictive(enum ieee80211_smps_mode smps_mode_old,
 
 	return false;
 }
+
+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_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;
+
+	if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+	    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
+		return -EOPNOTSUPP;
+
+	skb = dev_alloc_skb(local->tx_headroom + hdr_len +
+			    5 + /* channel switch announcement element */
+			    3 + /* secondary channel offset element */
+			    8); /* mesh channel switch parameters element */
+	if (!skb)
+		return -ENOMEM;
+
+	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);
+	if (ieee80211_vif_is_mesh(&sdata->vif)) {
+		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
+	} else {
+		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
+		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;
+	}
+
+	if (ieee80211_vif_is_mesh(&sdata->vif)) {
+		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+		__le16 pre_value;
+
+		skb_put(skb, 8);
+		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;		/* EID */
+		*pos++ = 6;					/* IE length */
+		*pos++ = sdata->u.mesh.mshcfg.dot11MeshTTL;	/* Mesh TTL */
+		*pos = 0x00;	/* Mesh Flag: Tx Restrict, Initiator, Reason */
+		*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
+		*pos++ |= csa_settings->block_tx ?
+			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
+		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos); /* Reason Cd */
+		pos += 2;
+		if (!ifmsh->pre_value)
+			ifmsh->pre_value = 1;
+		else
+			ifmsh->pre_value++;
+		pre_value = cpu_to_le16(ifmsh->pre_value);
+		memcpy(pos, &pre_value, 2);		/* Precedence Value */
+		pos += 2;
+		ifmsh->chsw_init = true;
+	}
+
+	ieee80211_tx_skb(sdata, skb);
+	return 0;
+}