mac80211: TDLS: handle chan-switch in RTNL locked work

Move TDLS channel-switch Rx handling into an RTNL locked work. This is
required to add proper regulatory checking to incoming channel-switch
requests.
Queue incoming requests in a dedicated skb queue and handle the request
in a device-specific work to avoid deadlocking on interface removal.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 90580e9..36f217e 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1008,7 +1008,6 @@ enum sdata_queue_type {
        IEEE80211_SDATA_QUEUE_AGG_STOP          = 2,
        IEEE80211_SDATA_QUEUE_RX_AGG_START      = 3,
        IEEE80211_SDATA_QUEUE_RX_AGG_STOP       = 4,
-       IEEE80211_SDATA_QUEUE_TDLS_CHSW         = 5,
 };
 
 enum {
@@ -1351,6 +1350,10 @@ struct ieee80211_local {
 
        /* extended capabilities provided by mac80211 */
        u8 ext_capa[8];
+
+       /* TDLS channel switch */
+       struct work_struct tdls_chsw_work;
+       struct sk_buff_head skb_queue_tdls_chsw;
 };
 
 static inline struct ieee80211_sub_if_data *
@@ -2054,9 +2057,8 @@ int ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy,
                                          struct net_device *dev,
                                          const u8 *addr);
-void ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata,
-                                          struct sk_buff *skb);
 void ieee80211_teardown_tdls_peers(struct ieee80211_sub_if_data *sdata);
+void ieee80211_tdls_chsw_work(struct work_struct *wk);
 
 extern const struct ethtool_ops ieee80211_ethtool_ops;
 

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 553ac6d..0fba7f9 100644 (file)
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1242,8 +1242,6 @@ static void ieee80211_iface_work(struct work_struct *work)
                                                        WLAN_BACK_RECIPIENT, 0,
                                                        false);
                        mutex_unlock(&local->sta_mtx);
-               } else if (skb->pkt_type == IEEE80211_SDATA_QUEUE_TDLS_CHSW) {
-                       ieee80211_process_tdls_channel_switch(sdata, skb);
                } else if (ieee80211_is_action(mgmt->frame_control) &&
                           mgmt->u.action.category == WLAN_CATEGORY_BACK) {
                        int len = skb->len;

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index dba0a86..ff79a13 100644 (file)
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -629,6 +629,8 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
        INIT_WORK(&local->sched_scan_stopped_work,
                  ieee80211_sched_scan_stopped_work);
 
+       INIT_WORK(&local->tdls_chsw_work, ieee80211_tdls_chsw_work);
+
        spin_lock_init(&local->ack_status_lock);
        idr_init(&local->ack_status_frames);
 
@@ -645,6 +647,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 
        skb_queue_head_init(&local->skb_queue);
        skb_queue_head_init(&local->skb_queue_unreliable);
+       skb_queue_head_init(&local->skb_queue_tdls_chsw);
 
        ieee80211_alloc_led_names(local);
 
@@ -1161,6 +1164,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
 
        cancel_work_sync(&local->restart_work);
        cancel_work_sync(&local->reconfig_filter);
+       cancel_work_sync(&local->tdls_chsw_work);
        flush_work(&local->sched_scan_stopped_work);
 
        ieee80211_clear_tx_pending(local);
@@ -1171,6 +1175,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
                wiphy_warn(local->hw.wiphy, "skb_queue not empty\n");
        skb_queue_purge(&local->skb_queue);
        skb_queue_purge(&local->skb_queue_unreliable);
+       skb_queue_purge(&local->skb_queue_tdls_chsw);
 
        destroy_workqueue(local->workqueue);
        wiphy_unregister(local->hw.wiphy);

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3a14628..f673304 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2410,9 +2410,8 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
                    tf->category == WLAN_CATEGORY_TDLS &&
                    (tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ||
                     tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE)) {
-                       rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TDLS_CHSW;
-                       skb_queue_tail(&sdata->skb_queue, rx->skb);
-                       ieee80211_queue_work(&rx->local->hw, &sdata->work);
+                       skb_queue_tail(&local->skb_queue_tdls_chsw, rx->skb);
+                       schedule_work(&local->tdls_chsw_work);
                        if (rx->sta)
                                rx->sta->rx_packets++;
 

diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index 20c9dbd..91e86bf 100644 (file)
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -12,6 +12,7 @@
 #include <linux/ieee80211.h>
 #include <linux/log2.h>
 #include <net/cfg80211.h>
+#include <linux/rtnetlink.h>
 #include "ieee80211_i.h"
 #include "driver-ops.h"
 
@@ -1800,12 +1801,15 @@ out:
        return ret;
 }
 
-void ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata,
-                                          struct sk_buff *skb)
+static void
+ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata,
+                                     struct sk_buff *skb)
 {
        struct ieee80211_tdls_data *tf = (void *)skb->data;
        struct wiphy *wiphy = sdata->local->hw.wiphy;
 
+       ASSERT_RTNL();
+
        /* make sure the driver supports it */
        if (!(wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
                return;
@@ -1847,3 +1851,29 @@ void ieee80211_teardown_tdls_peers(struct ieee80211_sub_if_data *sdata)
        }
        rcu_read_unlock();
 }
+
+void ieee80211_tdls_chsw_work(struct work_struct *wk)
+{
+       struct ieee80211_local *local =
+               container_of(wk, struct ieee80211_local, tdls_chsw_work);
+       struct ieee80211_sub_if_data *sdata;
+       struct sk_buff *skb;
+       struct ieee80211_tdls_data *tf;
+
+       rtnl_lock();
+       while ((skb = skb_dequeue(&local->skb_queue_tdls_chsw))) {
+               tf = (struct ieee80211_tdls_data *)skb->data;
+               list_for_each_entry(sdata, &local->interfaces, list) {
+                       if (!ieee80211_sdata_running(sdata) ||
+                           sdata->vif.type != NL80211_IFTYPE_STATION ||
+                           !ether_addr_equal(tf->da, sdata->vif.addr))
+                               continue;
+
+                       ieee80211_process_tdls_channel_switch(sdata, skb);
+                       break;
+               }
+
+               kfree_skb(skb);
+       }
+       rtnl_unlock();
+}