cfg80211: make regulatory_request use wiphy_idx instead of wiphy

We do this so later on we can move the pending requests onto a
workqueue. By using the wiphy_idx instead of the wiphy we can
later easily check if the wiphy has disappeared or not.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 79 insertions, 27 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index e347093ccc73..b1a354b7fc06 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -40,9 +40,8 @@ DEFINE_MUTEX(cfg80211_mutex);
 /* for debugfs */
 static struct dentry *ieee80211_debugfs_dir;
 
-/* requires cfg80211_drv_mutex to be held! */
-static struct cfg80211_registered_device *
-cfg80211_drv_by_wiphy_idx(int wiphy_idx)
+/* requires cfg80211_mutex to be held! */
+struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx)
 {
         struct cfg80211_registered_device *result = NULL, *drv;
 
@@ -61,6 +60,31 @@ cfg80211_drv_by_wiphy_idx(int wiphy_idx)
         return result;
 }
 
+int get_wiphy_idx(struct wiphy *wiphy)
+{
+        struct cfg80211_registered_device *drv;
+        if (!wiphy)
+                return WIPHY_IDX_STALE;
+        drv = wiphy_to_dev(wiphy);
+        return drv->wiphy_idx;
+}
+
+/* requires cfg80211_drv_mutex to be held! */
+struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
+{
+        struct cfg80211_registered_device *drv;
+
+        if (!wiphy_idx_valid(wiphy_idx))
+                return NULL;
+
+        assert_cfg80211_lock();
+
+        drv = cfg80211_drv_by_wiphy_idx(wiphy_idx);
+        if (!drv)
+                return NULL;
+        return &drv->wiphy;
+}
+
 /* requires cfg80211_mutex to be held! */
 static struct cfg80211_registered_device *
 __cfg80211_drv_from_info(struct genl_info *info)
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 982cc6be3484..cd8e6e3ef116 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -79,6 +79,12 @@ static inline void assert_cfg80211_lock(void)
         BUG_ON(!mutex_is_locked(&cfg80211_mutex));
 }
 
+/*
+ * You can use this to mark a wiphy_idx as not having an associated wiphy.
+ * It guarantees cfg80211_drv_by_wiphy_idx(wiphy_idx) will return NULL
+ */
+#define WIPHY_IDX_STALE -1
+
 struct cfg80211_internal_bss {
         struct list_head list;
         struct rb_node rbn;
@@ -88,6 +94,9 @@ struct cfg80211_internal_bss {
         struct cfg80211_bss pub;
 };
 
+struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx);
+int get_wiphy_idx(struct wiphy *wiphy);
+
 /*
  * This function returns a pointer to the driver
  * that the genl_info item that is passed refers to.
@@ -111,6 +120,9 @@ struct cfg80211_internal_bss {
 extern struct cfg80211_registered_device *
 cfg80211_get_dev_from_info(struct genl_info *info);
 
+/* requires cfg80211_drv_mutex to be held! */
+struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx);
+
 /* identical to cfg80211_get_dev_from_info but only operate on ifindex */
 extern struct cfg80211_registered_device *
 cfg80211_get_dev_from_ifindex(int ifindex);
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index e49ac9b2adac..d44f3b5481ad 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -831,9 +831,12 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
         const struct ieee80211_power_rule *power_rule = NULL;
         struct ieee80211_supported_band *sband;
         struct ieee80211_channel *chan;
+        struct wiphy *request_wiphy;
 
         assert_cfg80211_lock();
 
+        request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
+
         sband = wiphy->bands[band];
         BUG_ON(chan_idx >= sband->n_channels);
         chan = &sband->channels[chan_idx];
@@ -881,8 +884,8 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
         power_rule = &reg_rule->power_rule;
 
         if (last_request->initiator == REGDOM_SET_BY_DRIVER &&
-            last_request->wiphy && last_request->wiphy == wiphy &&
-            last_request->wiphy->strict_regulatory) {
+            request_wiphy && request_wiphy == wiphy &&
+            request_wiphy->strict_regulatory) {
                 /* This gaurantees the driver's requested regulatory domain
                  * will always be used as a base for further regulatory
                  * settings */
@@ -1046,6 +1049,7 @@ static int reg_copy_regd(const struct ieee80211_regdomain **dst_regd,
 static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
                           const char *alpha2)
 {
+        struct wiphy *last_wiphy = NULL;
 
         assert_cfg80211_lock();
 
@@ -1059,10 +1063,13 @@ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
         case REGDOM_SET_BY_CORE:
                 return -EINVAL;
         case REGDOM_SET_BY_COUNTRY_IE:
+
+                last_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
+
                 if (unlikely(!is_an_alpha2(alpha2)))
                         return -EINVAL;
                 if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
-                        if (last_request->wiphy != wiphy) {
+                        if (last_wiphy != wiphy) {
                                 /*
                                  * Two cards with two APs claiming different
                                  * different Country IE alpha2s. We could
@@ -1163,7 +1170,7 @@ new_request:
         request->alpha2[0] = alpha2[0];
         request->alpha2[1] = alpha2[1];
         request->initiator = set_by;
-        request->wiphy = wiphy;
+        request->wiphy_idx = get_wiphy_idx(wiphy);
         request->intersect = intersect;
         request->country_ie_checksum = country_ie_checksum;
         request->country_ie_env = env;
@@ -1226,11 +1233,16 @@ EXPORT_SYMBOL(regulatory_hint);
 static bool reg_same_country_ie_hint(struct wiphy *wiphy,
                         u32 country_ie_checksum)
 {
+        struct wiphy *request_wiphy;
+
         assert_cfg80211_lock();
 
-        if (!last_request->wiphy)
+        request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
+
+        if (!request_wiphy)
                 return false;
-        if (likely(last_request->wiphy != wiphy))
+
+        if (likely(request_wiphy != wiphy))
                 return !country_ie_integrity_changes(country_ie_checksum);
         /* We should not have let these through at this point, they
          * should have been picked up earlier by the first alpha2 check
@@ -1278,14 +1290,15 @@ void regulatory_hint_11d(struct wiphy *wiphy,
         /* We will run this for *every* beacon processed for the BSSID, so
          * we optimize an early check to exit out early if we don't have to
          * do anything */
-        if (likely(last_request->wiphy)) {
+        if (likely(wiphy_idx_valid(last_request->wiphy_idx))) {
                 struct cfg80211_registered_device *drv_last_ie;
 
-                drv_last_ie = wiphy_to_dev(last_request->wiphy);
+                drv_last_ie =
+                        cfg80211_drv_by_wiphy_idx(last_request->wiphy_idx);
 
                 /* Lets keep this simple -- we trust the first AP
                  * after we intersect with CRDA */
-                if (likely(last_request->wiphy == wiphy)) {
+                if (likely(&drv_last_ie->wiphy == wiphy)) {
                         /* Ignore IEs coming in on this wiphy with
                          * the same alpha2 and environment cap */
                         if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
@@ -1377,13 +1390,12 @@ static void print_regdomain(const struct ieee80211_regdomain *rd)
 {
 
         if (is_intersected_alpha2(rd->alpha2)) {
-                struct wiphy *wiphy = NULL;
-                struct cfg80211_registered_device *drv;
 
                 if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
-                        if (last_request->wiphy) {
-                                wiphy = last_request->wiphy;
-                                drv = wiphy_to_dev(wiphy);
+                        struct cfg80211_registered_device *drv;
+                        drv = cfg80211_drv_by_wiphy_idx(
+                                last_request->wiphy_idx);
+                        if (drv) {
                                 printk(KERN_INFO "cfg80211: Current regulatory "
                                         "domain updated by AP to: %c%c\n",
                                         drv->country_ie_alpha2[0],
@@ -1449,7 +1461,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
 {
         const struct ieee80211_regdomain *intersected_rd = NULL;
         struct cfg80211_registered_device *drv = NULL;
-        struct wiphy *wiphy = NULL;
+        struct wiphy *request_wiphy;
         /* Some basic sanity checks first */
 
         if (is_world_regdom(rd->alpha2)) {
@@ -1477,8 +1489,6 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
                         return -EINVAL;
         }
 
-        wiphy = last_request->wiphy;
-
         /* Now lets set the regulatory domain, update all driver channels
          * and finally inform them of what we have done, in case they want
          * to review or adjust their own settings based on their own
@@ -1494,6 +1504,8 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
                 return -EINVAL;
         }
 
+        request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
+
         if (!last_request->intersect) {
                 int r;
 
@@ -1506,9 +1518,9 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
                 /* For a driver hint, lets copy the regulatory domain the
                  * driver wanted to the wiphy to deal with conflicts */
 
-                BUG_ON(last_request->wiphy->regd);
+                BUG_ON(request_wiphy->regd);
 
-                r = reg_copy_regd(&last_request->wiphy->regd, rd);
+                r = reg_copy_regd(&request_wiphy->regd, rd);
                 if (r)
                         return r;
 
@@ -1529,7 +1541,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
                  * However if a driver requested this specific regulatory
                  * domain we keep it for its private use */
                 if (last_request->initiator == REGDOM_SET_BY_DRIVER)
-                        last_request->wiphy->regd = rd;
+                        request_wiphy->regd = rd;
                 else
                         kfree(rd);
 
@@ -1569,7 +1581,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
         if (!intersected_rd)
                 return -EINVAL;
 
-        drv = wiphy_to_dev(wiphy);
+        drv = wiphy_to_dev(request_wiphy);
 
         drv->country_ie_alpha2[0] = rd->alpha2[0];
         drv->country_ie_alpha2[1] = rd->alpha2[1];
@@ -1618,14 +1630,18 @@ int set_regdom(const struct ieee80211_regdomain *rd)
 /* Caller must hold cfg80211_mutex */
 void reg_device_remove(struct wiphy *wiphy)
 {
+        struct wiphy *request_wiphy;
+
         assert_cfg80211_lock();
 
+        request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
+
         kfree(wiphy->regd);
-        if (!last_request || !last_request->wiphy)
+        if (!last_request || !request_wiphy)
                 return;
-        if (last_request->wiphy != wiphy)
+        if (request_wiphy != wiphy)
                 return;
-        last_request->wiphy = NULL;
+        last_request->wiphy_idx = WIPHY_IDX_STALE;
         last_request->country_ie_env = ENVIRON_ANY;
 }