mac80211: Add HT helper functions

Some refactoring for IBSS HT.

Move HT info and capability IEs building code into separate functions.

Add function to get the channel type from an HT info IE.

Signed-off-by: Alexander Simon <an.alexsimon@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 99 insertions, 17 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 7439d26bf5f9..72b3a2ec0d24 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -811,23 +811,8 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 		offset = noffset;
 	}
 
-	if (sband->ht_cap.ht_supported) {
-		u16 cap = sband->ht_cap.cap;
-		__le16 tmp;
-
-		*pos++ = WLAN_EID_HT_CAPABILITY;
-		*pos++ = sizeof(struct ieee80211_ht_cap);
-		memset(pos, 0, sizeof(struct ieee80211_ht_cap));
-		tmp = cpu_to_le16(cap);
-		memcpy(pos, &tmp, sizeof(u16));
-		pos += sizeof(u16);
-		*pos++ = sband->ht_cap.ampdu_factor |
-			 (sband->ht_cap.ampdu_density <<
-				IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
-		memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
-		pos += sizeof(sband->ht_cap.mcs);
-		pos += 2 + 4 + 1; /* ext info, BF cap, antsel */
-	}
+	if (sband->ht_cap.ht_supported)
+		pos = ieee80211_ie_build_ht_cap(pos, sband, sband->ht_cap.cap);
 
 	/*
 	 * If adding more here, adjust code in main.c
@@ -1362,6 +1347,103 @@ void ieee80211_disable_rssi_reports(struct ieee80211_vif *vif)
 }
 EXPORT_SYMBOL(ieee80211_disable_rssi_reports);
 
+u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_supported_band *sband,
+			      u16 cap)
+{
+	__le16 tmp;
+
+	*pos++ = WLAN_EID_HT_CAPABILITY;
+	*pos++ = sizeof(struct ieee80211_ht_cap);
+	memset(pos, 0, sizeof(struct ieee80211_ht_cap));
+
+	/* capability flags */
+	tmp = cpu_to_le16(cap);
+	memcpy(pos, &tmp, sizeof(u16));
+	pos += sizeof(u16);
+
+	/* AMPDU parameters */
+	*pos++ = sband->ht_cap.ampdu_factor |
+		 (sband->ht_cap.ampdu_density <<
+			IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
+
+	/* MCS set */
+	memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
+	pos += sizeof(sband->ht_cap.mcs);
+
+	/* extended capabilities */
+	pos += sizeof(__le16);
+
+	/* BF capabilities */
+	pos += sizeof(__le32);
+
+	/* antenna selection */
+	pos += sizeof(u8);
+
+	return pos;
+}
+
+u8 *ieee80211_ie_build_ht_info(u8 *pos,
+			       struct ieee80211_sta_ht_cap *ht_cap,
+			       struct ieee80211_channel *channel,
+			       enum nl80211_channel_type channel_type)
+{
+	struct ieee80211_ht_info *ht_info;
+	/* Build HT Information */
+	*pos++ = WLAN_EID_HT_INFORMATION;
+	*pos++ = sizeof(struct ieee80211_ht_info);
+	ht_info = (struct ieee80211_ht_info *)pos;
+	ht_info->control_chan =
+			ieee80211_frequency_to_channel(channel->center_freq);
+	switch (channel_type) {
+	case NL80211_CHAN_HT40MINUS:
+		ht_info->ht_param = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
+		break;
+	case NL80211_CHAN_HT40PLUS:
+		ht_info->ht_param = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
+		break;
+	case NL80211_CHAN_HT20:
+	default:
+		ht_info->ht_param = IEEE80211_HT_PARAM_CHA_SEC_NONE;
+		break;
+	}
+	if (ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40)
+		ht_info->ht_param |= IEEE80211_HT_PARAM_CHAN_WIDTH_ANY;
+	ht_info->operation_mode = 0x0000;
+	ht_info->stbc_param = 0x0000;
+
+	/* It seems that Basic MCS set and Supported MCS set
+	   are identical for the first 10 bytes */
+	memset(&ht_info->basic_set, 0, 16);
+	memcpy(&ht_info->basic_set, &ht_cap->mcs, 10);
+
+	return pos + sizeof(struct ieee80211_ht_info);
+}
+
+enum nl80211_channel_type
+ieee80211_ht_info_to_channel_type(struct ieee80211_ht_info *ht_info)
+{
+	enum nl80211_channel_type channel_type;
+
+	if (!ht_info)
+		return NL80211_CHAN_NO_HT;
+
+	switch (ht_info->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
+	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
+		channel_type = NL80211_CHAN_HT20;
+		break;
+	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
+		channel_type = NL80211_CHAN_HT40PLUS;
+		break;
+	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+		channel_type = NL80211_CHAN_HT40MINUS;
+		break;
+	default:
+		channel_type = NL80211_CHAN_NO_HT;
+	}
+
+	return channel_type;
+}
+
 int ieee80211_add_srates_ie(struct ieee80211_vif *vif, struct sk_buff *skb)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);