mac80211: Support BIGTK configuration for Beacon protection

Extend mac80211 key configuration to support the new BIGTK with key
index values 6 and 7. Support for actually protecting Beacon frames
(adding the MME in AP mode and checking it in STA mode) is covered in
separate commits.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200222132548.20835-3-jouni@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

7 files changed, 104 insertions, 5 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index a66eff1..a762ba6 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -568,7 +568,8 @@ static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
 		if (pairwise && key_idx < NUM_DEFAULT_KEYS)
 			key = rcu_dereference(sta->ptk[key_idx]);
 		else if (!pairwise &&
-			 key_idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
+			 key_idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+			 NUM_DEFAULT_BEACON_KEYS)
 			key = rcu_dereference(sta->gtk[key_idx]);
 	} else
 		key = rcu_dereference(sdata->keys[key_idx]);
@@ -680,6 +681,17 @@ static int ieee80211_config_default_mgmt_key(struct wiphy *wiphy,
 	return 0;
 }
 
+static int ieee80211_config_default_beacon_key(struct wiphy *wiphy,
+					       struct net_device *dev,
+					       u8 key_idx)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	ieee80211_set_default_beacon_key(sdata, key_idx);
+
+	return 0;
+}
+
 void sta_set_rate_info_tx(struct sta_info *sta,
 			  const struct ieee80211_tx_rate *rate,
 			  struct rate_info *rinfo)
@@ -3885,6 +3897,7 @@ const struct cfg80211_ops mac80211_config_ops = {
 	.get_key = ieee80211_get_key,
 	.set_default_key = ieee80211_config_default_key,
 	.set_default_mgmt_key = ieee80211_config_default_mgmt_key,
+	.set_default_beacon_key = ieee80211_config_default_beacon_key,
 	.start_ap = ieee80211_start_ap,
 	.change_beacon = ieee80211_change_beacon,
 	.stop_ap = ieee80211_stop_ap,
diff --git a/net/mac80211/debugfs_key.c b/net/mac80211/debugfs_key.c
index 7b8735c..98a7134 100644
--- a/net/mac80211/debugfs_key.c
+++ b/net/mac80211/debugfs_key.c
@@ -433,6 +433,37 @@ void ieee80211_debugfs_key_remove_mgmt_default(struct ieee80211_sub_if_data *sda
 	sdata->debugfs.default_mgmt_key = NULL;
 }
 
+void
+ieee80211_debugfs_key_add_beacon_default(struct ieee80211_sub_if_data *sdata)
+{
+	char buf[50];
+	struct ieee80211_key *key;
+
+	if (!sdata->vif.debugfs_dir)
+		return;
+
+	key = key_mtx_dereference(sdata->local,
+				  sdata->default_beacon_key);
+	if (key) {
+		sprintf(buf, "../keys/%d", key->debugfs.cnt);
+		sdata->debugfs.default_beacon_key =
+			debugfs_create_symlink("default_beacon_key",
+					       sdata->vif.debugfs_dir, buf);
+	} else {
+		ieee80211_debugfs_key_remove_beacon_default(sdata);
+	}
+}
+
+void
+ieee80211_debugfs_key_remove_beacon_default(struct ieee80211_sub_if_data *sdata)
+{
+	if (!sdata)
+		return;
+
+	debugfs_remove(sdata->debugfs.default_beacon_key);
+	sdata->debugfs.default_beacon_key = NULL;
+}
+
 void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
 				   struct sta_info *sta)
 {
diff --git a/net/mac80211/debugfs_key.h b/net/mac80211/debugfs_key.h
index 1cd7b8b..af7cf49 100644
--- a/net/mac80211/debugfs_key.h
+++ b/net/mac80211/debugfs_key.h
@@ -10,6 +10,10 @@ void ieee80211_debugfs_key_add_mgmt_default(
 	struct ieee80211_sub_if_data *sdata);
 void ieee80211_debugfs_key_remove_mgmt_default(
 	struct ieee80211_sub_if_data *sdata);
+void ieee80211_debugfs_key_add_beacon_default(
+	struct ieee80211_sub_if_data *sdata);
+void ieee80211_debugfs_key_remove_beacon_default(
+	struct ieee80211_sub_if_data *sdata);
 void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
 				   struct sta_info *sta);
 #else
@@ -26,6 +30,12 @@ static inline void ieee80211_debugfs_key_add_mgmt_default(
 static inline void ieee80211_debugfs_key_remove_mgmt_default(
 	struct ieee80211_sub_if_data *sdata)
 {}
+static inline void ieee80211_debugfs_key_add_beacon_default(
+	struct ieee80211_sub_if_data *sdata)
+{}
+static inline void ieee80211_debugfs_key_remove_beacon_default(
+	struct ieee80211_sub_if_data *sdata)
+{}
 static inline void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
 						 struct sta_info *sta)
 {}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8a49d78..de39f9c 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -901,10 +901,13 @@ struct ieee80211_sub_if_data {
 	/* bit field of ACM bits (BIT(802.1D tag)) */
 	u8 wmm_acm;
 
-	struct ieee80211_key __rcu *keys[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
+	struct ieee80211_key __rcu *keys[NUM_DEFAULT_KEYS +
+					 NUM_DEFAULT_MGMT_KEYS +
+					 NUM_DEFAULT_BEACON_KEYS];
 	struct ieee80211_key __rcu *default_unicast_key;
 	struct ieee80211_key __rcu *default_multicast_key;
 	struct ieee80211_key __rcu *default_mgmt_key;
+	struct ieee80211_key __rcu *default_beacon_key;
 
 	u16 sequence_number;
 	__be16 control_port_protocol;
@@ -978,6 +981,7 @@ struct ieee80211_sub_if_data {
 		struct dentry *default_unicast_key;
 		struct dentry *default_multicast_key;
 		struct dentry *default_mgmt_key;
+		struct dentry *default_beacon_key;
 	} debugfs;
 #endif
 
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 54934ef..6354491 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -407,6 +407,31 @@ void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 	mutex_unlock(&sdata->local->key_mtx);
 }
 
+static void
+__ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata, int idx)
+{
+	struct ieee80211_key *key = NULL;
+
+	assert_key_lock(sdata->local);
+
+	if (idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS &&
+	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+	    NUM_DEFAULT_BEACON_KEYS)
+		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
+
+	rcu_assign_pointer(sdata->default_beacon_key, key);
+
+	ieee80211_debugfs_key_update_default(sdata);
+}
+
+void ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata,
+				      int idx)
+{
+	mutex_lock(&sdata->local->key_mtx);
+	__ieee80211_set_default_beacon_key(sdata, idx);
+	mutex_unlock(&sdata->local->key_mtx);
+}
+
 static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 				  struct sta_info *sta,
 				  bool pairwise,
@@ -415,7 +440,7 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 {
 	int idx;
 	int ret = 0;
-	bool defunikey, defmultikey, defmgmtkey;
+	bool defunikey, defmultikey, defmgmtkey, defbeaconkey;
 
 	/* caller must provide at least one old/new */
 	if (WARN_ON(!new && !old))
@@ -480,6 +505,9 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 		defmgmtkey = old &&
 			old == key_mtx_dereference(sdata->local,
 						sdata->default_mgmt_key);
+		defbeaconkey = old &&
+			old == key_mtx_dereference(sdata->local,
+						   sdata->default_beacon_key);
 
 		if (defunikey && !new)
 			__ieee80211_set_default_key(sdata, -1, true, false);
@@ -487,6 +515,8 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 			__ieee80211_set_default_key(sdata, -1, false, true);
 		if (defmgmtkey && !new)
 			__ieee80211_set_default_mgmt_key(sdata, -1);
+		if (defbeaconkey && !new)
+			__ieee80211_set_default_beacon_key(sdata, -1);
 
 		rcu_assign_pointer(sdata->keys[idx], new);
 		if (defunikey && new)
@@ -498,6 +528,9 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 		if (defmgmtkey && new)
 			__ieee80211_set_default_mgmt_key(sdata,
 							 new->conf.keyidx);
+		if (defbeaconkey && new)
+			__ieee80211_set_default_beacon_key(sdata,
+							   new->conf.keyidx);
 	}
 
 	if (old)
@@ -515,7 +548,9 @@ ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 	struct ieee80211_key *key;
 	int i, j, err;
 
-	if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
+	if (WARN_ON(idx < 0 ||
+		    idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+		    NUM_DEFAULT_BEACON_KEYS))
 		return ERR_PTR(-EINVAL);
 
 	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
@@ -978,6 +1013,7 @@ static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 	sdata->crypto_tx_tailroom_pending_dec = 0;
 
 	ieee80211_debugfs_key_remove_mgmt_default(sdata);
+	ieee80211_debugfs_key_remove_beacon_default(sdata);
 
 	list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 		ieee80211_key_replace(key->sdata, key->sta,
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index d6d6e89..7ad72e9 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -17,6 +17,7 @@
 
 #define NUM_DEFAULT_KEYS 4
 #define NUM_DEFAULT_MGMT_KEYS 2
+#define NUM_DEFAULT_BEACON_KEYS 2
 #define INVALID_PTK_KEYIDX 2 /* Keyidx always pointing to a NULL key for PTK */
 
 struct ieee80211_local;
@@ -153,6 +154,8 @@ void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 			       bool uni, bool multi);
 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 				    int idx);
+void ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata,
+				      int idx);
 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 			 bool force_synchronize);
 void ieee80211_free_sta_keys(struct ieee80211_local *local,
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index c00e285..364a354 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -533,7 +533,9 @@ struct sta_info {
 	u8 addr[ETH_ALEN];
 	struct ieee80211_local *local;
 	struct ieee80211_sub_if_data *sdata;
-	struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
+	struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS +
+					NUM_DEFAULT_MGMT_KEYS +
+					NUM_DEFAULT_BEACON_KEYS];
 	struct ieee80211_key __rcu *ptk[NUM_DEFAULT_KEYS];
 	u8 ptk_idx;
 	struct rate_control_ref *rate_ctrl;