1 files changed, 96 insertions, 29 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 659b507b347d..e9d040d29846 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -13,6 +13,7 @@
 #include <net/dsfield.h>
 #include <linux/if_vlan.h>
 #include <linux/mpls.h>
+#include <linux/gcd.h>
 #include "core.h"
 #include "rdev-ops.h"
 
@@ -1378,6 +1379,25 @@ static bool ieee80211_id_in_list(const u8 *ids, int n_ids, u8 id)
 	return false;
 }
 
+static size_t skip_ie(const u8 *ies, size_t ielen, size_t pos)
+{
+	/* we assume a validly formed IEs buffer */
+	u8 len = ies[pos + 1];
+
+	pos += 2 + len;
+
+	/* the IE itself must have 255 bytes for fragments to follow */
+	if (len < 255)
+		return pos;
+
+	while (pos < ielen && ies[pos] == WLAN_EID_FRAGMENT) {
+		len = ies[pos + 1];
+		pos += 2 + len;
+	}
+
+	return pos;
+}
+
 size_t ieee80211_ie_split_ric(const u8 *ies, size_t ielen,
 			      const u8 *ids, int n_ids,
 			      const u8 *after_ric, int n_after_ric,
@@ -1387,14 +1407,14 @@ size_t ieee80211_ie_split_ric(const u8 *ies, size_t ielen,
 
 	while (pos < ielen && ieee80211_id_in_list(ids, n_ids, ies[pos])) {
 		if (ies[pos] == WLAN_EID_RIC_DATA && n_after_ric) {
-			pos += 2 + ies[pos + 1];
+			pos = skip_ie(ies, ielen, pos);
 
 			while (pos < ielen &&
 			       !ieee80211_id_in_list(after_ric, n_after_ric,
 						     ies[pos]))
-				pos += 2 + ies[pos + 1];
+				pos = skip_ie(ies, ielen, pos);
 		} else {
-			pos += 2 + ies[pos + 1];
+			pos = skip_ie(ies, ielen, pos);
 		}
 	}
 
@@ -1555,31 +1575,57 @@ bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
 }
 EXPORT_SYMBOL(ieee80211_chandef_to_operating_class);
 
-int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
-				 u32 beacon_int)
+static void cfg80211_calculate_bi_data(struct wiphy *wiphy, u32 new_beacon_int,
+				       u32 *beacon_int_gcd,
+				       bool *beacon_int_different)
 {
 	struct wireless_dev *wdev;
-	int res = 0;
 
-	if (beacon_int < 10 || beacon_int > 10000)
-		return -EINVAL;
+	*beacon_int_gcd = 0;
+	*beacon_int_different = false;
 
-	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
+	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
 		if (!wdev->beacon_interval)
 			continue;
-		if (wdev->beacon_interval != beacon_int) {
-			res = -EINVAL;
-			break;
+
+		if (!*beacon_int_gcd) {
+			*beacon_int_gcd = wdev->beacon_interval;
+			continue;
 		}
+
+		if (wdev->beacon_interval == *beacon_int_gcd)
+			continue;
+
+		*beacon_int_different = true;
+		*beacon_int_gcd = gcd(*beacon_int_gcd, wdev->beacon_interval);
 	}
 
-	return res;
+	if (new_beacon_int && *beacon_int_gcd != new_beacon_int) {
+		if (*beacon_int_gcd)
+			*beacon_int_different = true;
+		*beacon_int_gcd = gcd(*beacon_int_gcd, new_beacon_int);
+	}
+}
+
+int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
+				 enum nl80211_iftype iftype, u32 beacon_int)
+{
+	/*
+	 * This is just a basic pre-condition check; if interface combinations
+	 * are possible the driver must already be checking those with a call
+	 * to cfg80211_check_combinations(), in which case we'll validate more
+	 * through the cfg80211_calculate_bi_data() call and code in
+	 * cfg80211_iter_combinations().
+	 */
+
+	if (beacon_int < 10 || beacon_int > 10000)
+		return -EINVAL;
+
+	return 0;
 }
 
 int cfg80211_iter_combinations(struct wiphy *wiphy,
-			       const int num_different_channels,
-			       const u8 radar_detect,
-			       const int iftype_num[NUM_NL80211_IFTYPES],
+			       struct iface_combination_params *params,
 			       void (*iter)(const struct ieee80211_iface_combination *c,
 					    void *data),
 			       void *data)
@@ -1589,8 +1635,23 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 	int i, j, iftype;
 	int num_interfaces = 0;
 	u32 used_iftypes = 0;
+	u32 beacon_int_gcd;
+	bool beacon_int_different;
+
+	/*
+	 * This is a bit strange, since the iteration used to rely only on
+	 * the data given by the driver, but here it now relies on context,
+	 * in form of the currently operating interfaces.
+	 * This is OK for all current users, and saves us from having to
+	 * push the GCD calculations into all the drivers.
+	 * In the future, this should probably rely more on data that's in
+	 * cfg80211 already - the only thing not would appear to be any new
+	 * interfaces (while being brought up) and channel/radar data.
+	 */
+	cfg80211_calculate_bi_data(wiphy, params->new_beacon_int,
+				   &beacon_int_gcd, &beacon_int_different);
 
-	if (radar_detect) {
+	if (params->radar_detect) {
 		rcu_read_lock();
 		regdom = rcu_dereference(cfg80211_regdomain);
 		if (regdom)
@@ -1599,8 +1660,8 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 	}
 
 	for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
-		num_interfaces += iftype_num[iftype];
-		if (iftype_num[iftype] > 0 &&
+		num_interfaces += params->iftype_num[iftype];
+		if (params->iftype_num[iftype] > 0 &&
 		    !(wiphy->software_iftypes & BIT(iftype)))
 			used_iftypes |= BIT(iftype);
 	}
@@ -1614,7 +1675,7 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 
 		if (num_interfaces > c->max_interfaces)
 			continue;
-		if (num_different_channels > c->num_different_channels)
+		if (params->num_different_channels > c->num_different_channels)
 			continue;
 
 		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
@@ -1629,16 +1690,17 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 				all_iftypes |= limits[j].types;
 				if (!(limits[j].types & BIT(iftype)))
 					continue;
-				if (limits[j].max < iftype_num[iftype])
+				if (limits[j].max < params->iftype_num[iftype])
 					goto cont;
-				limits[j].max -= iftype_num[iftype];
+				limits[j].max -= params->iftype_num[iftype];
 			}
 		}
 
-		if (radar_detect != (c->radar_detect_widths & radar_detect))
+		if (params->radar_detect !=
+			(c->radar_detect_widths & params->radar_detect))
 			goto cont;
 
-		if (radar_detect && c->radar_detect_regions &&
+		if (params->radar_detect && c->radar_detect_regions &&
 		    !(c->radar_detect_regions & BIT(region)))
 			goto cont;
 
@@ -1650,6 +1712,14 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
 		if ((all_iftypes & used_iftypes) != used_iftypes)
 			goto cont;
 
+		if (beacon_int_gcd) {
+			if (c->beacon_int_min_gcd &&
+			    beacon_int_gcd < c->beacon_int_min_gcd)
+				goto cont;
+			if (!c->beacon_int_min_gcd && beacon_int_different)
+				goto cont;
+		}
+
 		/* This combination covered all interface types and
 		 * supported the requested numbers, so we're good.
 		 */
@@ -1672,14 +1742,11 @@ cfg80211_iter_sum_ifcombs(const struct ieee80211_iface_combination *c,
 }
 
 int cfg80211_check_combinations(struct wiphy *wiphy,
-				const int num_different_channels,
-				const u8 radar_detect,
-				const int iftype_num[NUM_NL80211_IFTYPES])
+				struct iface_combination_params *params)
 {
 	int err, num = 0;
 
-	err = cfg80211_iter_combinations(wiphy, num_different_channels,
-					 radar_detect, iftype_num,
+	err = cfg80211_iter_combinations(wiphy, params,
 					 cfg80211_iter_sum_ifcombs, &num);
 	if (err)
 		return err;