{nl,mac}80211: fix interface combinations on crypto controlled devices

Commit 33d915d9e8ce ("{nl,mac}80211: allow 4addr AP operation on
crypto controlled devices") has introduced a change which allows
4addr operation on crypto controlled devices (ex: ath10k). This
change has inadvertently impacted the interface combinations logic
on such devices.

General rule is that software interfaces like AP/VLAN should not be
listed under supported interface combinations and should not be
considered during validation of these combinations; because of the
aforementioned change, AP/VLAN interfaces(if present) will be checked
against interfaces supported by the device and blocks valid interface
combinations.

Consider a case where an AP and AP/VLAN are up and running; when a
second AP device is brought up on the same physical device, this AP
will be checked against the AP/VLAN interface (which will not be
part of supported interface combinations of the device) and blocks
second AP to come up.

Add a new API cfg80211_iftype_allowed() to fix the problem, this
API works for all devices with/without SW crypto control.

Signed-off-by: Manikanta Pubbisetty <mpubbise@codeaurora.org>
Fixes: 33d915d9e8ce ("{nl,mac}80211: allow 4addr AP operation on crypto controlled devices")
Link: https://lore.kernel.org/r/1563779690-9716-1-git-send-email-mpubbise@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 28 insertions, 9 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 45d9afcff6d5..32b3c719fdfc 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1410,10 +1410,8 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		}
 		break;
 	case NETDEV_PRE_UP:
-		if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)) &&
-		    !(wdev->iftype == NL80211_IFTYPE_AP_VLAN &&
-		      rdev->wiphy.flags & WIPHY_FLAG_4ADDR_AP &&
-		      wdev->use_4addr))
+		if (!cfg80211_iftype_allowed(wdev->wiphy, wdev->iftype,
+					     wdev->use_4addr, 0))
 			return notifier_from_errno(-EOPNOTSUPP);
 
 		if (rfkill_blocked(rdev->rfkill))
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index fc83dd179c1a..fd05ae1437a9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3484,9 +3484,7 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
 			return err;
 	}
 
-	if (!(rdev->wiphy.interface_modes & (1 << type)) &&
-	    !(type == NL80211_IFTYPE_AP_VLAN && params.use_4addr &&
-	      rdev->wiphy.flags & WIPHY_FLAG_4ADDR_AP))
+	if (!cfg80211_iftype_allowed(&rdev->wiphy, type, params.use_4addr, 0))
 		return -EOPNOTSUPP;
 
 	err = nl80211_parse_mon_options(rdev, type, info, &params);
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 1c39d6a2e850..d0e35b7b9e35 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1697,7 +1697,7 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 	for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
 		num_interfaces += params->iftype_num[iftype];
 		if (params->iftype_num[iftype] > 0 &&
-		    !(wiphy->software_iftypes & BIT(iftype)))
+		    !cfg80211_iftype_allowed(wiphy, iftype, 0, 1))
 			used_iftypes |= BIT(iftype);
 	}
 
@@ -1719,7 +1719,7 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 			return -ENOMEM;
 
 		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
-			if (wiphy->software_iftypes & BIT(iftype))
+			if (cfg80211_iftype_allowed(wiphy, iftype, 0, 1))
 				continue;
 			for (j = 0; j < c->n_limits; j++) {
 				all_iftypes |= limits[j].types;
@@ -2072,3 +2072,26 @@ int ieee80211_get_vht_max_nss(struct ieee80211_vht_cap *cap,
 	return max_vht_nss;
 }
 EXPORT_SYMBOL(ieee80211_get_vht_max_nss);
+
+bool cfg80211_iftype_allowed(struct wiphy *wiphy, enum nl80211_iftype iftype,
+			     bool is_4addr, u8 check_swif)
+
+{
+	bool is_vlan = iftype == NL80211_IFTYPE_AP_VLAN;
+
+	switch (check_swif) {
+	case 0:
+		if (is_vlan && is_4addr)
+			return wiphy->flags & WIPHY_FLAG_4ADDR_AP;
+		return wiphy->interface_modes & BIT(iftype);
+	case 1:
+		if (!(wiphy->software_iftypes & BIT(iftype)) && is_vlan)
+			return wiphy->flags & WIPHY_FLAG_4ADDR_AP;
+		return wiphy->software_iftypes & BIT(iftype);
+	default:
+		break;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(cfg80211_iftype_allowed);