cfg80211/mac80211: move more combination checks to mac80211

Get rid of the cfg80211_can_add_interface() and
cfg80211_can_change_interface() functions by moving that functionality
to mac80211.  With this patch all interface combination checks are now
out of cfg80211 (except for the channel switch case which will be
addressed in a future commit).

Additionally, modify the ieee80211_check_combinations() function so
that an undefined chandef can be passed, in order to use it before a
channel is defined.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

7 files changed, 26 insertions, 42 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 8bf94eaa0456..23d60110aebd 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -109,6 +109,15 @@ static int ieee80211_change_iface(struct wiphy *wiphy,
 static int ieee80211_start_p2p_device(struct wiphy *wiphy,
                                       struct wireless_dev *wdev)
 {
+        struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+        int ret;
+
+        mutex_lock(&sdata->local->chanctx_mtx);
+        ret = ieee80211_check_combinations(sdata, NULL, 0, 0);
+        mutex_unlock(&sdata->local->chanctx_mtx);
+        if (ret < 0)
+                return ret;
+
         return ieee80211_do_open(wdev, true);
 }
 
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 4826c8f5d0b2..ad5badd783d8 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -250,6 +250,7 @@ static int ieee80211_check_concurrent_iface(struct ieee80211_sub_if_data *sdata,
 {
         struct ieee80211_local *local = sdata->local;
         struct ieee80211_sub_if_data *nsdata;
+        int ret;
 
         ASSERT_RTNL();
 
@@ -300,7 +301,10 @@ static int ieee80211_check_concurrent_iface(struct ieee80211_sub_if_data *sdata,
                 }
         }
 
-        return 0;
+        mutex_lock(&local->chanctx_mtx);
+        ret = ieee80211_check_combinations(sdata, NULL, 0, 0);
+        mutex_unlock(&local->chanctx_mtx);
+        return ret;
 }
 
 static int ieee80211_check_queues(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 436f98870066..5a6cc3382ae9 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2808,7 +2808,7 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
         enum nl80211_iftype iftype = sdata->wdev.iftype;
         int num[NUM_NL80211_IFTYPES];
         struct ieee80211_chanctx *ctx;
-        int num_different_channels = 1;
+        int num_different_channels = 0;
         int total = 1;
 
         lockdep_assert_held(&local->chanctx_mtx);
@@ -2816,9 +2816,13 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
         if (WARN_ON(hweight32(radar_detect) > 1))
                 return -EINVAL;
 
-        if (WARN_ON(chanmode == IEEE80211_CHANCTX_SHARED && !chandef->chan))
+        if (WARN_ON(chandef && chanmode == IEEE80211_CHANCTX_SHARED &&
+                    !chandef->chan))
                 return -EINVAL;
 
+        if (chandef)
+                num_different_channels = 1;
+
         if (WARN_ON(iftype >= NUM_NL80211_IFTYPES))
                 return -EINVAL;
 
@@ -2841,7 +2845,7 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
                         num_different_channels++;
                         continue;
                 }
-                if ((chanmode == IEEE80211_CHANCTX_SHARED) &&
+                if (chandef && chanmode == IEEE80211_CHANCTX_SHARED &&
                     cfg80211_chandef_compatible(chandef,
                                                 &ctx->conf.def))
                         continue;
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 5a63c3cbda2e..33d12e23771c 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -439,10 +439,7 @@ static int wiphy_verify_combinations(struct wiphy *wiphy)
                 for (j = 0; j < c->n_limits; j++) {
                         u16 types = c->limits[j].types;
 
-                        /*
-                         * interface types shouldn't overlap, this is
-                         * used in cfg80211_can_change_interface()
-                         */
+                        /* interface types shouldn't overlap */
                         if (WARN_ON(types & all_iftypes))
                                 return -EINVAL;
                         all_iftypes |= types;
@@ -840,7 +837,6 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         struct cfg80211_registered_device *rdev;
-        int ret;
 
         if (!wdev)
                 return NOTIFY_DONE;
@@ -1003,9 +999,8 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
         case NETDEV_PRE_UP:
                 if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
                         return notifier_from_errno(-EOPNOTSUPP);
-                ret = cfg80211_can_add_interface(rdev, wdev->iftype);
-                if (ret)
-                        return notifier_from_errno(ret);
+                if (rfkill_blocked(rdev->rfkill))
+                        return notifier_from_errno(-ERFKILL);
                 break;
         }
 
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 6684c5d965d8..5bee6cc94b21 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -412,28 +412,6 @@ unsigned int
 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
                               const struct cfg80211_chan_def *chandef);
 
-static inline int
-cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
-                              struct wireless_dev *wdev,
-                              enum nl80211_iftype iftype)
-{
-        /* TODO: For this function, we'll probably need to keep some
-         * kind of interface combination check in cfg80211...
-         */
-        return cfg80211_can_use_iftype_chan(rdev, wdev, iftype, NULL,
-                                            CHAN_MODE_UNDEFINED, 0);
-}
-
-static inline int
-cfg80211_can_add_interface(struct cfg80211_registered_device *rdev,
-                           enum nl80211_iftype iftype)
-{
-        if (rfkill_blocked(rdev->rfkill))
-                return -ERFKILL;
-
-        return cfg80211_can_change_interface(rdev, NULL, iftype);
-}
-
 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 {
         unsigned long end = jiffies;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2b99aad33ae0..232d15c0ac6e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -8969,9 +8969,8 @@ static int nl80211_start_p2p_device(struct sk_buff *skb, struct genl_info *info)
         if (wdev->p2p_started)
                 return 0;
 
-        err = cfg80211_can_add_interface(rdev, wdev->iftype);
-        if (err)
-                return err;
+        if (rfkill_blocked(rdev->rfkill))
+                return -ERFKILL;
 
         err = rdev_start_p2p_device(rdev, wdev);
         if (err)
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 9bfc4c621509..5433659a08ee 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -888,11 +888,6 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
                 return -EBUSY;
 
         if (ntype != otype && netif_running(dev)) {
-                err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
-                                                    ntype);
-                if (err)
-                        return err;
-
                 dev->ieee80211_ptr->use_4addr = false;
                 dev->ieee80211_ptr->mesh_id_up_len = 0;
                 wdev_lock(dev->ieee80211_ptr);