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);
 }