cfg80211: Clean up connect params and channel fetching

Addition of the frequency hints showed up couple of places in cfg80211
where pointers could be marked const and a shared function could be used
to fetch a valid channel.
Signed-off-by: Jouni Malinen <j@w1.fi>
[fix mwifiex]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -1583,8 +1583,9 @@ static int mwifiex_cfg80211_inform_ibss_bss(struct mwifiex_private *priv)
  * the function notifies the CFG802.11 subsystem of the new BSS connection.
  */
 static int
-mwifiex_cfg80211_assoc(struct mwifiex_private *priv, size_t ssid_len, u8 *ssid,
-		       u8 *bssid, int mode, struct ieee80211_channel *channel,
+mwifiex_cfg80211_assoc(struct mwifiex_private *priv, size_t ssid_len,
+		       const u8 *ssid, const u8 *bssid, int mode,
+		       struct ieee80211_channel *channel,
 		       struct cfg80211_connect_params *sme, bool privacy)
 {
 	struct cfg80211_ssid req_ssid;

include/net/cfg80211.h

@@ -1732,9 +1732,9 @@ struct cfg80211_ibss_params {
 struct cfg80211_connect_params {
 	struct ieee80211_channel *channel;
 	struct ieee80211_channel *channel_hint;
-	u8 *bssid;
+	const u8 *bssid;
 	const u8 *bssid_hint;
-	u8 *ssid;
+	const u8 *ssid;
 	size_t ssid_len;
 	enum nl80211_auth_type auth_type;
 	u8 *ie;

net/wireless/nl80211.c

@@ -857,6 +857,19 @@ static int nl80211_key_allowed(struct wireless_dev *wdev)
 	return 0;
 }
 
+static struct ieee80211_channel *nl80211_get_valid_chan(struct wiphy *wiphy,
+							struct nlattr *tb)
+{
+	struct ieee80211_channel *chan;
+
+	if (tb == NULL)
+		return NULL;
+	chan = ieee80211_get_channel(wiphy, nla_get_u32(tb));
+	if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
+		return NULL;
+	return chan;
+}
+
 static int nl80211_put_iftypes(struct sk_buff *msg, u32 attr, u16 ifmodes)
 {
 	struct nlattr *nl_modes = nla_nest_start(msg, attr);
@@ -6199,9 +6212,9 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 		return -EOPNOTSUPP;
 
 	bssid = nla_data(info->attrs[NL80211_ATTR_MAC]);
-	chan = ieee80211_get_channel(&rdev->wiphy,
-		nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
-	if (!chan || (chan->flags & IEEE80211_CHAN_DISABLED))
+	chan = nl80211_get_valid_chan(&rdev->wiphy,
+				      info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+	if (!chan)
 		return -EINVAL;
 
 	ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
@@ -6354,9 +6367,9 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
 
 	bssid = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	chan = ieee80211_get_channel(&rdev->wiphy,
-		nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
-	if (!chan || (chan->flags & IEEE80211_CHAN_DISABLED))
+	chan = nl80211_get_valid_chan(&rdev->wiphy,
+				      info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+	if (!chan)
 		return -EINVAL;
 
 	ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
@@ -7013,19 +7026,14 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
-		connect.channel =
-			ieee80211_get_channel(wiphy,
-			    nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
-		if (!connect.channel ||
-		    connect.channel->flags & IEEE80211_CHAN_DISABLED)
+		connect.channel = nl80211_get_valid_chan(
+			wiphy, info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+		if (!connect.channel)
 			return -EINVAL;
 	} else if (info->attrs[NL80211_ATTR_WIPHY_FREQ_HINT]) {
-		connect.channel_hint =
-			ieee80211_get_channel(wiphy,
-			    nla_get_u32(
-				    info->attrs[NL80211_ATTR_WIPHY_FREQ_HINT]));
-		if (!connect.channel_hint ||
-		    connect.channel_hint->flags & IEEE80211_CHAN_DISABLED)
+		connect.channel_hint = nl80211_get_valid_chan(
+			wiphy, info->attrs[NL80211_ATTR_WIPHY_FREQ_HINT]);
+		if (!connect.channel_hint)
 			return -EINVAL;
 	}