cfg80211: provide channel to join_mesh function

Just like the AP mode patch, instead of setting
the channel and then joining the mesh network,
provide the channel to join the network on to
the join_mesh() function.

Like in AP mode, you can also give the channel
to the join-mesh nl80211 command now.

Unlike AP mode, it picks a default channel if
none was given.

As libertas uses mesh mode interfaces but has
no join_mesh callback and we can't simply break
it, keep some compatibility code for that case
and configure the channel directly for it.

In the non-libertas case, where we store the
channel until join, allow setting it while the
interface is down.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 33 insertions, 10 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 089a5204dad5..b22f1f876881 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -921,7 +921,8 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 		if (nla_put_u32(msg, i, NL80211_CMD_SET_WIPHY_NETNS))
 			goto nla_put_failure;
 	}
-	if (dev->ops->set_channel || dev->ops->start_ap) {
+	if (dev->ops->set_channel || dev->ops->start_ap ||
+	    dev->ops->join_mesh) {
 		i++;
 		if (nla_put_u32(msg, i, NL80211_CMD_SET_CHANNEL))
 			goto nla_put_failure;
@@ -1166,17 +1167,19 @@ static int parse_txq_params(struct nlattr *tb[],
 static bool nl80211_can_set_dev_channel(struct wireless_dev *wdev)
 {
 	/*
-	 * You can only set the channel explicitly for AP and
-	 * mesh type interfaces; all others have their channel
-	 * managed via their respective "establish a connection"
-	 * command (connect, join, ...)
+	 * You can only set the channel explicitly for WDS interfaces,
+	 * all others have their channel managed via their respective
+	 * "establish a connection" command (connect, join, ...)
+	 *
+	 * For AP/GO and mesh mode, the channel can be set with the
+	 * channel userspace API, but is only stored and passed to the
+	 * low-level driver when the AP starts or the mesh is joined.
+	 * This is for backward compatibility, userspace can also give
+	 * the channel in the start-ap or join-mesh commands instead.
 	 *
 	 * Monitors are special as they are normally slaved to
 	 * whatever else is going on, so they behave as though
 	 * you tried setting the wiphy channel itself.
-	 *
-	 * For AP/GO modes, it's only for compatibility, you can
-	 * also give the channel to the start-AP command.
 	 */
 	return !wdev ||
 		wdev->iftype == NL80211_IFTYPE_AP ||
@@ -1246,6 +1249,9 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 		wdev->preset_chantype = channel_type;
 		result = 0;
 		break;
+	case NL80211_IFTYPE_MESH_POINT:
+		result = cfg80211_set_mesh_freq(rdev, wdev, freq, channel_type);
+		break;
 	default:
 		wdev_lock(wdev);
 		result = cfg80211_set_freq(rdev, wdev, freq, channel_type);
@@ -1335,8 +1341,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 		result = 0;
 
 		mutex_lock(&rdev->mtx);
-	} else if (netif_running(netdev) &&
-		   nl80211_can_set_dev_channel(netdev->ieee80211_ptr))
+	} else if (nl80211_can_set_dev_channel(netdev->ieee80211_ptr))
 		wdev = netdev->ieee80211_ptr;
 	else
 		wdev = NULL;
@@ -6080,6 +6085,24 @@ static int nl80211_join_mesh(struct sk_buff *skb, struct genl_info *info)
 			return err;
 	}
 
+	if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
+		enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
+
+		if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE] &&
+		    !nl80211_valid_channel_type(info, &channel_type))
+			return -EINVAL;
+
+		setup.channel = rdev_freq_to_chan(rdev,
+			nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]),
+			channel_type);
+		if (!setup.channel)
+			return -EINVAL;
+		setup.channel_type = channel_type;
+	} else {
+		/* cfg80211_join_mesh() will sort it out */
+		setup.channel = NULL;
+	}
+
 	return cfg80211_join_mesh(rdev, dev, &setup, &cfg);
 }