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, 89 insertions, 2 deletions

diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 2749cb86b46..2e3b700eba3 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -65,6 +65,9 @@ const struct mesh_config default_mesh_config = {
 };
 
 const struct mesh_setup default_mesh_setup = {
+        /* cfg80211_join_mesh() will pick a channel if needed */
+        .channel = NULL,
+        .channel_type = NL80211_CHAN_NO_HT,
         .sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
         .path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
         .path_metric = IEEE80211_PATH_METRIC_AIRTIME,
@@ -75,7 +78,7 @@ const struct mesh_setup default_mesh_setup = {
 
 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
                          struct net_device *dev,
-                         const struct mesh_setup *setup,
+                         struct mesh_setup *setup,
                          const struct mesh_config *conf)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
@@ -101,6 +104,51 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
         if (!rdev->ops->join_mesh)
                 return -EOPNOTSUPP;
 
+        if (!setup->channel) {
+                /* if no channel explicitly given, use preset channel */
+                setup->channel = wdev->preset_chan;
+                setup->channel_type = wdev->preset_chantype;
+        }
+
+        if (!setup->channel) {
+                /* if we don't have that either, use the first usable channel */
+                enum ieee80211_band band;
+
+                for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+                        struct ieee80211_supported_band *sband;
+                        struct ieee80211_channel *chan;
+                        int i;
+
+                        sband = rdev->wiphy.bands[band];
+                        if (!sband)
+                                continue;
+
+                        for (i = 0; i < sband->n_channels; i++) {
+                                chan = &sband->channels[i];
+                                if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
+                                                   IEEE80211_CHAN_PASSIVE_SCAN |
+                                                   IEEE80211_CHAN_DISABLED |
+                                                   IEEE80211_CHAN_RADAR))
+                                        continue;
+                                setup->channel = chan;
+                                break;
+                        }
+
+                        if (setup->channel)
+                                break;
+                }
+
+                /* no usable channel ... */
+                if (!setup->channel)
+                        return -EINVAL;
+
+                setup->channel_type = NL80211_CHAN_NO_HT;
+        }
+
+        if (!cfg80211_can_beacon_sec_chan(&rdev->wiphy, setup->channel,
+                                          setup->channel_type))
+                return -EINVAL;
+
         err = rdev->ops->join_mesh(&rdev->wiphy, dev, conf, setup);
         if (!err) {
                 memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
@@ -112,7 +160,7 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 
 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
                        struct net_device *dev,
-                       const struct mesh_setup *setup,
+                       struct mesh_setup *setup,
                        const struct mesh_config *conf)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
@@ -125,6 +173,45 @@ int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
         return err;
 }
 
+int cfg80211_set_mesh_freq(struct cfg80211_registered_device *rdev,
+                           struct wireless_dev *wdev, int freq,
+                           enum nl80211_channel_type channel_type)
+{
+        struct ieee80211_channel *channel;
+
+        /*
+         * Workaround for libertas (only!), it puts the interface
+         * into mesh mode but doesn't implement join_mesh. Instead,
+         * it is configured via sysfs and then joins the mesh when
+         * you set the channel. Note that the libertas mesh isn't
+         * compatible with 802.11 mesh.
+         */
+        if (!rdev->ops->join_mesh) {
+                int err;
+
+                if (!netif_running(wdev->netdev))
+                        return -ENETDOWN;
+                wdev_lock(wdev);
+                err = cfg80211_set_freq(rdev, wdev, freq, channel_type);
+                wdev_unlock(wdev);
+
+                return err;
+        }
+
+        if (wdev->mesh_id_len)
+                return -EBUSY;
+
+        channel = rdev_freq_to_chan(rdev, freq, channel_type);
+        if (!channel || !cfg80211_can_beacon_sec_chan(&rdev->wiphy,
+                                                      channel,
+                                                      channel_type)) {
+                return -EINVAL;
+        }
+        wdev->preset_chan = channel;
+        wdev->preset_chantype = channel_type;
+        return 0;
+}
+
 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
                 const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
 {