wifi: mac80211: refactor some key code

There's some pretty close code here, with the exception
of RCU dereference vs. protected dereference. Refactor
this to just return a pointer and then do the deref in
the caller later.

Change-Id: Ide5315e2792da6ac66eaf852293306a3ac71ced9
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f3b10cee929937cc11dafe7929160d3bd4efa8b6..881efbfb96f6d96ffa7c1edf8afc75f0730a096c 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -533,33 +533,53 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
        return err;
 }
 
+static struct ieee80211_key *
+ieee80211_lookup_key(struct ieee80211_sub_if_data *sdata,
+                    u8 key_idx, bool pairwise, const u8 *mac_addr)
+{
+       struct ieee80211_local *local = sdata->local;
+       struct sta_info *sta;
+
+       if (mac_addr) {
+               sta = sta_info_get_bss(sdata, mac_addr);
+               if (!sta)
+                       return NULL;
+
+               if (pairwise && key_idx < NUM_DEFAULT_KEYS)
+                       return rcu_dereference_check_key_mtx(local,
+                                                            sta->ptk[key_idx]);
+
+               if (!pairwise &&
+                   key_idx < NUM_DEFAULT_KEYS +
+                             NUM_DEFAULT_MGMT_KEYS +
+                             NUM_DEFAULT_BEACON_KEYS)
+                       return rcu_dereference_check_key_mtx(local,
+                                                            sta->deflink.gtk[key_idx]);
+
+               return NULL;
+       }
+
+       if (key_idx < NUM_DEFAULT_KEYS +
+                     NUM_DEFAULT_MGMT_KEYS +
+                     NUM_DEFAULT_BEACON_KEYS)
+               return rcu_dereference_check_key_mtx(local,
+                                                    sdata->keys[key_idx]);
+
+       return NULL;
+}
+
 static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
                             u8 key_idx, bool pairwise, const u8 *mac_addr)
 {
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        struct ieee80211_local *local = sdata->local;
-       struct sta_info *sta;
-       struct ieee80211_key *key = NULL;
+       struct ieee80211_key *key;
        int ret;
 
        mutex_lock(&local->sta_mtx);
        mutex_lock(&local->key_mtx);
 
-       if (mac_addr) {
-               ret = -ENOENT;
-
-               sta = sta_info_get_bss(sdata, mac_addr);
-               if (!sta)
-                       goto out_unlock;
-
-               if (pairwise)
-                       key = key_mtx_dereference(local, sta->ptk[key_idx]);
-               else
-                       key = key_mtx_dereference(local,
-                                                 sta->deflink.gtk[key_idx]);
-       } else
-               key = key_mtx_dereference(local, sdata->keys[key_idx]);
-
+       key = ieee80211_lookup_key(sdata, key_idx, pairwise, mac_addr);
        if (!key) {
                ret = -ENOENT;
                goto out_unlock;
@@ -582,10 +602,9 @@ static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
                                              struct key_params *params))
 {
        struct ieee80211_sub_if_data *sdata;
-       struct sta_info *sta = NULL;
        u8 seq[6] = {0};
        struct key_params params;
-       struct ieee80211_key *key = NULL;
+       struct ieee80211_key *key;
        u64 pn64;
        u32 iv32;
        u16 iv16;
@@ -596,20 +615,7 @@ static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
 
        rcu_read_lock();
 
-       if (mac_addr) {
-               sta = sta_info_get_bss(sdata, mac_addr);
-               if (!sta)
-                       goto out;
-
-               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 +
-                        NUM_DEFAULT_BEACON_KEYS)
-                       key = rcu_dereference(sta->deflink.gtk[key_idx]);
-       } else
-               key = rcu_dereference(sdata->keys[key_idx]);
-
+       key = ieee80211_lookup_key(sdata, key_idx, pairwise, mac_addr);
        if (!key)
                goto out;
 

diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index b3fb41c0c77fd98b62ba9ce8fcc2e52e934c8184..e994dcea1ce3aed51bbf691fd5aa17ce7b40575d 100644 (file)
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -163,6 +163,8 @@ void ieee80211_reenable_keys(struct ieee80211_sub_if_data *sdata);
 
 #define key_mtx_dereference(local, ref) \
        rcu_dereference_protected(ref, lockdep_is_held(&((local)->key_mtx)))
+#define rcu_dereference_check_key_mtx(local, ref) \
+       rcu_dereference_check(ref, lockdep_is_held(&((local)->key_mtx)))
 
 void ieee80211_delayed_tailroom_dec(struct work_struct *wk);