cfg80211: allow continuous radar monitoring on offchannel chain

Allow continuous radar detection on the offchannel chain in order
to switch to the monitored channel whenever the underlying driver
reports a radar pattern on the main channel.

Tested-by: Owen Peng <owen.peng@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/d46217310a49b14ff0e9c002f0a6e0547d70fd2c.1637071350.git.lorenzo@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 869c43d..00fc7b7 100644 (file)
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -712,6 +712,19 @@ static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
        return false;
 }
 
+static bool
+cfg80211_offchan_chain_is_active(struct cfg80211_registered_device *rdev,
+                                struct ieee80211_channel *channel)
+{
+       if (!rdev->offchan_radar_wdev)
+               return false;
+
+       if (!cfg80211_chandef_valid(&rdev->offchan_radar_chandef))
+               return false;
+
+       return cfg80211_is_sub_chan(&rdev->offchan_radar_chandef, channel);
+}
+
 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
                                  struct ieee80211_channel *chan)
 {
@@ -728,6 +741,9 @@ bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
 
                if (cfg80211_is_wiphy_oper_chan(&rdev->wiphy, chan))
                        return true;
+
+               if (cfg80211_offchan_chain_is_active(rdev, chan))
+                       return true;
        }
 
        return false;

diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 450be1e..e970076 100644 (file)
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -988,7 +988,7 @@ __cfg80211_offchan_cac_event(struct cfg80211_registered_device *rdev,
        if (!cfg80211_chandef_valid(chandef))
                return;
 
-       if (event != NL80211_RADAR_CAC_STARTED && !rdev->offchan_radar_wdev)
+       if (!rdev->offchan_radar_wdev)
                return;
 
        switch (event) {
@@ -998,17 +998,13 @@ __cfg80211_offchan_cac_event(struct cfg80211_registered_device *rdev,
                queue_work(cfg80211_wq, &rdev->propagate_cac_done_wk);
                cfg80211_sched_dfs_chan_update(rdev);
                wdev = rdev->offchan_radar_wdev;
-               rdev->offchan_radar_wdev = NULL;
                break;
        case NL80211_RADAR_CAC_ABORTED:
                if (!cancel_delayed_work(&rdev->offchan_cac_done_wk))
                        return;
                wdev = rdev->offchan_radar_wdev;
-               rdev->offchan_radar_wdev = NULL;
                break;
        case NL80211_RADAR_CAC_STARTED:
-               WARN_ON(!wdev);
-               rdev->offchan_radar_wdev = wdev;
                break;
        default:
                return;
@@ -1024,7 +1020,8 @@ cfg80211_offchan_cac_event(struct cfg80211_registered_device *rdev,
                           enum nl80211_radar_event event)
 {
        wiphy_lock(&rdev->wiphy);
-       __cfg80211_offchan_cac_event(rdev, NULL, chandef, event);
+       __cfg80211_offchan_cac_event(rdev, rdev->offchan_radar_wdev,
+                                    chandef, event);
        wiphy_unlock(&rdev->wiphy);
 }
 
@@ -1071,7 +1068,13 @@ cfg80211_start_offchan_radar_detection(struct cfg80211_registered_device *rdev,
                                     NL80211_EXT_FEATURE_RADAR_OFFCHAN))
                return -EOPNOTSUPP;
 
-       if (rdev->offchan_radar_wdev)
+       /* Offchannel chain already locked by another wdev */
+       if (rdev->offchan_radar_wdev && rdev->offchan_radar_wdev != wdev)
+               return -EBUSY;
+
+       /* CAC already in progress on the offchannel chain */
+       if (rdev->offchan_radar_wdev == wdev &&
+           delayed_work_pending(&rdev->offchan_cac_done_wk))
                return -EBUSY;
 
        err = rdev_set_radar_offchan(rdev, chandef);
@@ -1083,6 +1086,8 @@ cfg80211_start_offchan_radar_detection(struct cfg80211_registered_device *rdev,
                cac_time_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
 
        rdev->offchan_radar_chandef = *chandef;
+       rdev->offchan_radar_wdev = wdev; /* Get offchain ownership */
+
        __cfg80211_offchan_cac_event(rdev, wdev, chandef,
                                     NL80211_RADAR_CAC_STARTED);
        queue_delayed_work(cfg80211_wq, &rdev->offchan_cac_done_wk,
@@ -1102,6 +1107,7 @@ void cfg80211_stop_offchan_radar_detection(struct wireless_dev *wdev)
                return;
 
        rdev_set_radar_offchan(rdev, NULL);
+       rdev->offchan_radar_wdev = NULL; /* Release offchain ownership */
 
        __cfg80211_offchan_cac_event(rdev, wdev, &rdev->offchan_radar_chandef,
                                     NL80211_RADAR_CAC_ABORTED);

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 83a1ba9..65693c9 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -9275,42 +9275,60 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
        struct cfg80211_chan_def chandef;
        enum nl80211_dfs_regions dfs_region;
        unsigned int cac_time_ms;
-       int err;
+       int err = -EINVAL;
+
+       flush_delayed_work(&rdev->dfs_update_channels_wk);
+
+       wiphy_lock(wiphy);
 
        dfs_region = reg_get_dfs_region(wiphy);
        if (dfs_region == NL80211_DFS_UNSET)
-               return -EINVAL;
+               goto unlock;
 
        err = nl80211_parse_chandef(rdev, info, &chandef);
        if (err)
-               return err;
+               goto unlock;
 
        err = cfg80211_chandef_dfs_required(wiphy, &chandef, wdev->iftype);
        if (err < 0)
-               return err;
+               goto unlock;
 
-       if (err == 0)
-               return -EINVAL;
+       if (err == 0) {
+               err = -EINVAL;
+               goto unlock;
+       }
 
-       if (!cfg80211_chandef_dfs_usable(wiphy, &chandef))
-               return -EINVAL;
+       if (!cfg80211_chandef_dfs_usable(wiphy, &chandef)) {
+               err = -EINVAL;
+               goto unlock;
+       }
 
-       if (nla_get_flag(info->attrs[NL80211_ATTR_RADAR_OFFCHAN]))
-               return cfg80211_start_offchan_radar_detection(rdev, wdev,
-                                                             &chandef);
+       if (nla_get_flag(info->attrs[NL80211_ATTR_RADAR_OFFCHAN])) {
+               err = cfg80211_start_offchan_radar_detection(rdev, wdev,
+                                                            &chandef);
+               goto unlock;
+       }
 
-       if (netif_carrier_ok(dev))
-               return -EBUSY;
+       if (netif_carrier_ok(dev)) {
+               err = -EBUSY;
+               goto unlock;
+       }
 
-       if (wdev->cac_started)
-               return -EBUSY;
+       if (wdev->cac_started) {
+               err = -EBUSY;
+               goto unlock;
+       }
 
        /* CAC start is offloaded to HW and can't be started manually */
-       if (wiphy_ext_feature_isset(wiphy, NL80211_EXT_FEATURE_DFS_OFFLOAD))
-               return -EOPNOTSUPP;
+       if (wiphy_ext_feature_isset(wiphy, NL80211_EXT_FEATURE_DFS_OFFLOAD)) {
+               err = -EOPNOTSUPP;
+               goto unlock;
+       }
 
-       if (!rdev->ops->start_radar_detection)
-               return -EOPNOTSUPP;
+       if (!rdev->ops->start_radar_detection) {
+               err = -EOPNOTSUPP;
+               goto unlock;
+       }
 
        cac_time_ms = cfg80211_chandef_dfs_cac_time(&rdev->wiphy, &chandef);
        if (WARN_ON(!cac_time_ms))
@@ -9323,6 +9341,9 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
                wdev->cac_start_time = jiffies;
                wdev->cac_time_ms = cac_time_ms;
        }
+unlock:
+       wiphy_unlock(wiphy);
+
        return err;
 }
 
@@ -15959,7 +15980,8 @@ static const struct genl_small_ops nl80211_small_ops[] = {
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = nl80211_start_radar_detection,
                .flags = GENL_UNS_ADMIN_PERM,
-               .internal_flags = NL80211_FLAG_NEED_NETDEV_UP,
+               .internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+                                 NL80211_FLAG_NO_WIPHY_MTX,
        },
        {
                .cmd = NL80211_CMD_GET_PROTOCOL_FEATURES,