nl80211: use attributes to parse beacons

only the attributes are required and not the whole netlink info, as the
function accesses the attributes only anyway. This makes it easier to
parse nested beacon IEs later.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -2882,61 +2882,58 @@ static int nl80211_set_mac_acl(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
-static int nl80211_parse_beacon(struct genl_info *info,
+static int nl80211_parse_beacon(struct nlattr *attrs[],
 				struct cfg80211_beacon_data *bcn)
 {
 	bool haveinfo = false;
 
-	if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_BEACON_TAIL]) ||
-	    !is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]) ||
-	    !is_valid_ie_attr(info->attrs[NL80211_ATTR_IE_PROBE_RESP]) ||
-	    !is_valid_ie_attr(info->attrs[NL80211_ATTR_IE_ASSOC_RESP]))
+	if (!is_valid_ie_attr(attrs[NL80211_ATTR_BEACON_TAIL]) ||
+	    !is_valid_ie_attr(attrs[NL80211_ATTR_IE]) ||
+	    !is_valid_ie_attr(attrs[NL80211_ATTR_IE_PROBE_RESP]) ||
+	    !is_valid_ie_attr(attrs[NL80211_ATTR_IE_ASSOC_RESP]))
 		return -EINVAL;
 
 	memset(bcn, 0, sizeof(*bcn));
 
-	if (info->attrs[NL80211_ATTR_BEACON_HEAD]) {
-		bcn->head = nla_data(info->attrs[NL80211_ATTR_BEACON_HEAD]);
-		bcn->head_len = nla_len(info->attrs[NL80211_ATTR_BEACON_HEAD]);
+	if (attrs[NL80211_ATTR_BEACON_HEAD]) {
+		bcn->head = nla_data(attrs[NL80211_ATTR_BEACON_HEAD]);
+		bcn->head_len = nla_len(attrs[NL80211_ATTR_BEACON_HEAD]);
 		if (!bcn->head_len)
 			return -EINVAL;
 		haveinfo = true;
 	}
 
-	if (info->attrs[NL80211_ATTR_BEACON_TAIL]) {
-		bcn->tail = nla_data(info->attrs[NL80211_ATTR_BEACON_TAIL]);
-		bcn->tail_len =
-		    nla_len(info->attrs[NL80211_ATTR_BEACON_TAIL]);
+	if (attrs[NL80211_ATTR_BEACON_TAIL]) {
+		bcn->tail = nla_data(attrs[NL80211_ATTR_BEACON_TAIL]);
+		bcn->tail_len = nla_len(attrs[NL80211_ATTR_BEACON_TAIL]);
 		haveinfo = true;
 	}
 
 	if (!haveinfo)
 		return -EINVAL;
 
-	if (info->attrs[NL80211_ATTR_IE]) {
-		bcn->beacon_ies = nla_data(info->attrs[NL80211_ATTR_IE]);
-		bcn->beacon_ies_len = nla_len(info->attrs[NL80211_ATTR_IE]);
+	if (attrs[NL80211_ATTR_IE]) {
+		bcn->beacon_ies = nla_data(attrs[NL80211_ATTR_IE]);
+		bcn->beacon_ies_len = nla_len(attrs[NL80211_ATTR_IE]);
 	}
 
-	if (info->attrs[NL80211_ATTR_IE_PROBE_RESP]) {
+	if (attrs[NL80211_ATTR_IE_PROBE_RESP]) {
 		bcn->proberesp_ies =
-			nla_data(info->attrs[NL80211_ATTR_IE_PROBE_RESP]);
+			nla_data(attrs[NL80211_ATTR_IE_PROBE_RESP]);
 		bcn->proberesp_ies_len =
-			nla_len(info->attrs[NL80211_ATTR_IE_PROBE_RESP]);
+			nla_len(attrs[NL80211_ATTR_IE_PROBE_RESP]);
 	}
 
-	if (info->attrs[NL80211_ATTR_IE_ASSOC_RESP]) {
+	if (attrs[NL80211_ATTR_IE_ASSOC_RESP]) {
 		bcn->assocresp_ies =
-			nla_data(info->attrs[NL80211_ATTR_IE_ASSOC_RESP]);
+			nla_data(attrs[NL80211_ATTR_IE_ASSOC_RESP]);
 		bcn->assocresp_ies_len =
-			nla_len(info->attrs[NL80211_ATTR_IE_ASSOC_RESP]);
+			nla_len(attrs[NL80211_ATTR_IE_ASSOC_RESP]);
 	}
 
-	if (info->attrs[NL80211_ATTR_PROBE_RESP]) {
-		bcn->probe_resp =
-			nla_data(info->attrs[NL80211_ATTR_PROBE_RESP]);
-		bcn->probe_resp_len =
-			nla_len(info->attrs[NL80211_ATTR_PROBE_RESP]);
+	if (attrs[NL80211_ATTR_PROBE_RESP]) {
+		bcn->probe_resp = nla_data(attrs[NL80211_ATTR_PROBE_RESP]);
+		bcn->probe_resp_len = nla_len(attrs[NL80211_ATTR_PROBE_RESP]);
 	}
 
 	return 0;
@@ -3015,7 +3012,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	    !info->attrs[NL80211_ATTR_BEACON_HEAD])
 		return -EINVAL;
 
-	err = nl80211_parse_beacon(info, &params.beacon);
+	err = nl80211_parse_beacon(info->attrs, &params.beacon);
 	if (err)
 		return err;
 
@@ -3167,7 +3164,7 @@ static int nl80211_set_beacon(struct sk_buff *skb, struct genl_info *info)
 	if (!wdev->beacon_interval)
 		return -EINVAL;
 
-	err = nl80211_parse_beacon(info, &params);
+	err = nl80211_parse_beacon(info->attrs, &params);
 	if (err)
 		return err;