nl80211: Add basic rate configuration for AP mode

Add a new attribute, NL80211_ATTR_BSS_BASIC_RATES, that can be used with
NL80211_CMD_SET_BSS for userspace (e.g., hostapd) to set which rates are
in the basic rate set.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/linux/nl80211.h

@@ -243,6 +243,9 @@ enum nl80211_commands {
  *	(u8, 0 or 1)
  * @NL80211_ATTR_BSS_SHORT_SLOT_TIME: whether short slot time enabled
  *	(u8, 0 or 1)
+ * @NL80211_ATTR_BSS_BASIC_RATES: basic rates, array of basic
+ *	rates in format defined by IEEE 802.11 7.3.2.2 but without the length
+ *	restriction (at most %NL80211_MAX_SUPP_RATES).
  *
  * @NL80211_ATTR_HT_CAPABILITY: HT Capability information element (from
  *	association request when used with NL80211_CMD_NEW_STATION)
@@ -307,6 +310,8 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_MESH_PARAMS,
 
+	NL80211_ATTR_BSS_BASIC_RATES,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -318,6 +323,7 @@ enum nl80211_attrs {
  * here
  */
 #define NL80211_ATTR_HT_CAPABILITY NL80211_ATTR_HT_CAPABILITY
+#define NL80211_ATTR_BSS_BASIC_RATES NL80211_ATTR_BSS_BASIC_RATES
 
 #define NL80211_MAX_SUPP_RATES			32
 #define NL80211_MAX_SUPP_REG_RULES		32

include/net/cfg80211.h

@@ -280,11 +280,16 @@ struct mpath_info {
  *	(0 = no, 1 = yes, -1 = do not change)
  * @use_short_slot_time: Whether the use of short slot time is allowed
  *	(0 = no, 1 = yes, -1 = do not change)
+ * @basic_rates: basic rates in IEEE 802.11 format
+ *	(or NULL for no change)
+ * @basic_rates_len: number of basic rates
  */
 struct bss_parameters {
 	int use_cts_prot;
 	int use_short_preamble;
 	int use_short_slot_time;
+	u8 *basic_rates;
+	u8 basic_rates_len;
 };
 
 /**

net/mac80211/cfg.c

@@ -1046,6 +1046,24 @@ static int ieee80211_change_bss(struct wiphy *wiphy,
 		changed |= BSS_CHANGED_ERP_SLOT;
 	}
 
+	if (params->basic_rates) {
+		int i, j;
+		u32 rates = 0;
+		struct ieee80211_local *local = wiphy_priv(wiphy);
+		struct ieee80211_supported_band *sband =
+			wiphy->bands[local->oper_channel->band];
+
+		for (i = 0; i < params->basic_rates_len; i++) {
+			int rate = (params->basic_rates[i] & 0x7f) * 5;
+			for (j = 0; j < sband->n_bitrates; j++) {
+				if (sband->bitrates[j].bitrate == rate)
+					rates |= BIT(j);
+			}
+		}
+		sdata->vif.bss_conf.basic_rates = rates;
+		changed |= BSS_CHANGED_BASIC_RATES;
+	}
+
 	ieee80211_bss_info_change_notify(sdata, changed);
 
 	return 0;

net/wireless/nl80211.c

@@ -95,6 +95,8 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
 	[NL80211_ATTR_BSS_CTS_PROT] = { .type = NLA_U8 },
 	[NL80211_ATTR_BSS_SHORT_PREAMBLE] = { .type = NLA_U8 },
 	[NL80211_ATTR_BSS_SHORT_SLOT_TIME] = { .type = NLA_U8 },
+	[NL80211_ATTR_BSS_BASIC_RATES] = { .type = NLA_BINARY,
+					   .len = NL80211_MAX_SUPP_RATES },
 
 	[NL80211_ATTR_MESH_PARAMS] = { .type = NLA_NESTED },
 
@@ -1613,6 +1615,12 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_BSS_SHORT_SLOT_TIME])
 		params.use_short_slot_time =
 		    nla_get_u8(info->attrs[NL80211_ATTR_BSS_SHORT_SLOT_TIME]);
+	if (info->attrs[NL80211_ATTR_BSS_BASIC_RATES]) {
+		params.basic_rates =
+			nla_data(info->attrs[NL80211_ATTR_BSS_BASIC_RATES]);
+		params.basic_rates_len =
+			nla_len(info->attrs[NL80211_ATTR_BSS_BASIC_RATES]);
+	}
 
 	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)