5 files changed, 254 insertions, 4 deletions

diff --git a/include/net/wireless.h b/include/net/wireless.h
index 1f4707d18adb..64a76208580c 100644
--- a/include/net/wireless.h
+++ b/include/net/wireless.h
@@ -69,6 +69,9 @@ enum ieee80211_channel_flags {
  * @band: band this channel belongs to.
  * @max_antenna_gain: maximum antenna gain in dBi
  * @max_power: maximum transmission power (in dBm)
+ * @beacon_found: helper to regulatory code to indicate when a beacon
+ *      has been found on this channel. Use regulatory_hint_found_beacon()
+ *      to enable this, this is is useful only on 5 GHz band.
  * @orig_mag: internal use
  * @orig_mpwr: internal use
  */
@@ -80,6 +83,7 @@ struct ieee80211_channel {
         u32 flags;
         int max_antenna_gain;
         int max_power;
+        bool beacon_found;
         u32 orig_flags;
         int orig_mag, orig_mpwr;
 };
@@ -425,7 +429,6 @@ extern int regulatory_hint(struct wiphy *wiphy, const char *alpha2);
 extern void regulatory_hint_11d(struct wiphy *wiphy,
                                 u8 *country_ie,
                                 u8 country_ie_len);
-
 /**
  * wiphy_apply_custom_regulatory - apply a custom driver regulatory domain
  * @wiphy: the wireless device we want to process the regulatory domain on
diff --git a/net/wireless/core.c b/net/wireless/core.c
index b1a354b7fc06..dd7f222919fe 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -32,8 +32,9 @@ MODULE_DESCRIPTION("wireless configuration support");
 LIST_HEAD(cfg80211_drv_list);
 
 /*
- * This is used to protect the cfg80211_drv_list, cfg80211_regdomain, and
- * the last reguluatory request receipt in regd.c
+ * This is used to protect the cfg80211_drv_list, cfg80211_regdomain,
+ * country_ie_regdomain, the reg_beacon_list and the the last regulatory
+ * request receipt (last_request).
  */
 DEFINE_MUTEX(cfg80211_mutex);
 
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index da2a8aca4280..e5e432d6af34 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -68,9 +68,22 @@ const struct ieee80211_regdomain *cfg80211_regdomain;
  */
 static const struct ieee80211_regdomain *country_ie_regdomain;
 
+/* Used to queue up regulatory hints */
 static LIST_HEAD(reg_requests_list);
 static spinlock_t reg_requests_lock;
 
+/* Used to queue up beacon hints for review */
+static LIST_HEAD(reg_pending_beacons);
+static spinlock_t reg_pending_beacons_lock;
+
+/* Used to keep track of processed beacon hints */
+static LIST_HEAD(reg_beacon_list);
+
+struct reg_beacon {
+        struct list_head list;
+        struct ieee80211_channel chan;
+};
+
 /* We keep a static world regulatory domain in case of the absence of CRDA */
 static const struct ieee80211_regdomain world_regdom = {
         .n_reg_rules = 3,
@@ -1011,16 +1024,120 @@ static void update_all_wiphy_regulatory(enum reg_set_by setby)
                 wiphy_update_regulatory(&drv->wiphy, setby);
 }
 
+static void handle_reg_beacon(struct wiphy *wiphy,
+                              unsigned int chan_idx,
+                              struct reg_beacon *reg_beacon)
+{
+#ifdef CONFIG_CFG80211_REG_DEBUG
+#define REG_DEBUG_BEACON_FLAG(desc) \
+        printk(KERN_DEBUG "cfg80211: Enabling " desc " on " \
+                "frequency: %d MHz (Ch %d) on %s\n", \
+                reg_beacon->chan.center_freq, \
+                ieee80211_frequency_to_channel(reg_beacon->chan.center_freq), \
+                wiphy_name(wiphy));
+#else
+#define REG_DEBUG_BEACON_FLAG(desc) do {} while (0)
+#endif
+        struct ieee80211_supported_band *sband;
+        struct ieee80211_channel *chan;
+
+        assert_cfg80211_lock();
+
+        sband = wiphy->bands[reg_beacon->chan.band];
+        chan = &sband->channels[chan_idx];
+
+        if (likely(chan->center_freq != reg_beacon->chan.center_freq))
+                return;
+
+        if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) {
+                chan->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
+                REG_DEBUG_BEACON_FLAG("active scanning");
+        }
+
+        if (chan->flags & IEEE80211_CHAN_NO_IBSS) {
+                chan->flags &= ~IEEE80211_CHAN_NO_IBSS;
+                REG_DEBUG_BEACON_FLAG("beaconing");
+        }
+
+        chan->beacon_found = true;
+#undef REG_DEBUG_BEACON_FLAG
+}
+
+/*
+ * Called when a scan on a wiphy finds a beacon on
+ * new channel
+ */
+static void wiphy_update_new_beacon(struct wiphy *wiphy,
+                                    struct reg_beacon *reg_beacon)
+{
+        unsigned int i;
+        struct ieee80211_supported_band *sband;
+
+        assert_cfg80211_lock();
+
+        if (!wiphy->bands[reg_beacon->chan.band])
+                return;
+
+        sband = wiphy->bands[reg_beacon->chan.band];
+
+        for (i = 0; i < sband->n_channels; i++)
+                handle_reg_beacon(wiphy, i, reg_beacon);
+}
+
+/*
+ * Called upon reg changes or a new wiphy is added
+ */
+static void wiphy_update_beacon_reg(struct wiphy *wiphy)
+{
+        unsigned int i;
+        struct ieee80211_supported_band *sband;
+        struct reg_beacon *reg_beacon;
+
+        assert_cfg80211_lock();
+
+        if (list_empty(&reg_beacon_list))
+                return;
+
+        list_for_each_entry(reg_beacon, &reg_beacon_list, list) {
+                if (!wiphy->bands[reg_beacon->chan.band])
+                        continue;
+                sband = wiphy->bands[reg_beacon->chan.band];
+                for (i = 0; i < sband->n_channels; i++)
+                        handle_reg_beacon(wiphy, i, reg_beacon);
+        }
+}
+
+static bool reg_is_world_roaming(struct wiphy *wiphy)
+{
+        if (is_world_regdom(cfg80211_regdomain->alpha2) ||
+            (wiphy->regd && is_world_regdom(wiphy->regd->alpha2)))
+                return true;
+        if (last_request->initiator != REGDOM_SET_BY_COUNTRY_IE &&
+            wiphy->custom_regulatory)
+                return true;
+        return false;
+}
+
+/* Reap the advantages of previously found beacons */
+static void reg_process_beacons(struct wiphy *wiphy)
+{
+        if (!reg_is_world_roaming(wiphy))
+                return;
+        wiphy_update_beacon_reg(wiphy);
+}
+
 void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby)
 {
         enum ieee80211_band band;
 
         if (ignore_reg_update(wiphy, setby))
-                return;
+                goto out;
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                 if (wiphy->bands[band])
                         handle_band(wiphy, band);
         }
+out:
+        reg_process_beacons(wiphy);
         if (wiphy->reg_notifier)
                 wiphy->reg_notifier(wiphy, last_request);
 }
@@ -1314,6 +1431,7 @@ out:
         return r;
 }
 
+/* Processes regulatory hints, this is all the REGDOM_SET_BY_* */
 static void reg_process_pending_hints(void)
         {
         struct regulatory_request *reg_request;
@@ -1344,9 +1462,44 @@ static void reg_process_pending_hints(void)
         spin_unlock(&reg_requests_lock);
 }
 
+/* Processes beacon hints -- this has nothing to do with country IEs */
+static void reg_process_pending_beacon_hints(void)
+{
+        struct cfg80211_registered_device *drv;
+        struct reg_beacon *pending_beacon, *tmp;
+
+        mutex_lock(&cfg80211_mutex);
+
+        /* This goes through the _pending_ beacon list */
+        spin_lock_bh(&reg_pending_beacons_lock);
+
+        if (list_empty(&reg_pending_beacons)) {
+                spin_unlock_bh(&reg_pending_beacons_lock);
+                goto out;
+        }
+
+        list_for_each_entry_safe(pending_beacon, tmp,
+                                 &reg_pending_beacons, list) {
+
+                list_del_init(&pending_beacon->list);
+
+                /* Applies the beacon hint to current wiphys */
+                list_for_each_entry(drv, &cfg80211_drv_list, list)
+                        wiphy_update_new_beacon(&drv->wiphy, pending_beacon);
+
+                /* Remembers the beacon hint for new wiphys or reg changes */
+                list_add_tail(&pending_beacon->list, &reg_beacon_list);
+        }
+
+        spin_unlock_bh(&reg_pending_beacons_lock);
+out:
+        mutex_unlock(&cfg80211_mutex);
+}
+
 static void reg_todo(struct work_struct *work)
 {
         reg_process_pending_hints();
+        reg_process_pending_beacon_hints();
 }
 
 static DECLARE_WORK(reg_work, reg_todo);
@@ -1587,6 +1740,55 @@ out:
 }
 EXPORT_SYMBOL(regulatory_hint_11d);
 
+static bool freq_is_chan_12_13_14(u16 freq)
+{
+        if (freq == ieee80211_channel_to_frequency(12) ||
+            freq == ieee80211_channel_to_frequency(13) ||
+            freq == ieee80211_channel_to_frequency(14))
+                return true;
+        return false;
+}
+
+int regulatory_hint_found_beacon(struct wiphy *wiphy,
+                                 struct ieee80211_channel *beacon_chan,
+                                 gfp_t gfp)
+{
+        struct reg_beacon *reg_beacon;
+
+        if (likely((beacon_chan->beacon_found ||
+            (beacon_chan->flags & IEEE80211_CHAN_RADAR) ||
+            (beacon_chan->band == IEEE80211_BAND_2GHZ &&
+             !freq_is_chan_12_13_14(beacon_chan->center_freq)))))
+                return 0;
+
+        reg_beacon = kzalloc(sizeof(struct reg_beacon), gfp);
+        if (!reg_beacon)
+                return -ENOMEM;
+
+#ifdef CONFIG_CFG80211_REG_DEBUG
+        printk(KERN_DEBUG "cfg80211: Found new beacon on "
+                "frequency: %d MHz (Ch %d) on %s\n",
+                beacon_chan->center_freq,
+                ieee80211_frequency_to_channel(beacon_chan->center_freq),
+                wiphy_name(wiphy));
+#endif
+        memcpy(&reg_beacon->chan, beacon_chan,
+                sizeof(struct ieee80211_channel));
+
+
+        /*
+         * Since we can be called from BH or and non-BH context
+         * we must use spin_lock_bh()
+         */
+        spin_lock_bh(&reg_pending_beacons_lock);
+        list_add_tail(&reg_beacon->list, &reg_pending_beacons);
+        spin_unlock_bh(&reg_pending_beacons_lock);
+
+        schedule_work(&reg_work);
+
+        return 0;
+}
+
 static void print_rd_rules(const struct ieee80211_regdomain *rd)
 {
         unsigned int i;
@@ -1908,6 +2110,7 @@ int regulatory_init(void)
                 return PTR_ERR(reg_pdev);
 
         spin_lock_init(&reg_requests_lock);
+        spin_lock_init(&reg_pending_beacons_lock);
 
 #ifdef CONFIG_WIRELESS_OLD_REGULATORY
         cfg80211_regdomain = static_regdom(ieee80211_regdom);
@@ -1951,6 +2154,7 @@ int regulatory_init(void)
 void regulatory_exit(void)
 {
         struct regulatory_request *reg_request, *tmp;
+        struct reg_beacon *reg_beacon, *btmp;
 
         cancel_work_sync(&reg_work);
 
@@ -1965,6 +2169,24 @@ void regulatory_exit(void)
 
         platform_device_unregister(reg_pdev);
 
+        spin_lock_bh(&reg_pending_beacons_lock);
+        if (!list_empty(&reg_pending_beacons)) {
+                list_for_each_entry_safe(reg_beacon, btmp,
+                                         &reg_pending_beacons, list) {
+                        list_del(&reg_beacon->list);
+                        kfree(reg_beacon);
+                }
+        }
+        spin_unlock_bh(&reg_pending_beacons_lock);
+
+        if (!list_empty(&reg_beacon_list)) {
+                list_for_each_entry_safe(reg_beacon, btmp,
+                                         &reg_beacon_list, list) {
+                        list_del(&reg_beacon->list);
+                        kfree(reg_beacon);
+                }
+        }
+
         spin_lock(&reg_requests_lock);
         if (!list_empty(&reg_requests_list)) {
                 list_for_each_entry_safe(reg_request, tmp,
diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index 4730def5a69d..65bfd0558ce1 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -38,4 +38,25 @@ extern int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
                              const char *alpha2, u32 country_ie_checksum,
                              enum environment_cap country_ie_env);
 
+/**
+ * regulatory_hint_found_beacon - hints a beacon was found on a channel
+ * @wiphy: the wireless device where the beacon was found on
+ * @beacon_chan: the channel on which the beacon was found on
+ * @gfp: context flags
+ *
+ * This informs the wireless core that a beacon from an AP was found on
+ * the channel provided. This allows the wireless core to make educated
+ * guesses on regulatory to help with world roaming. This is only used for
+ * world roaming -- when we do not know our current location. This is
+ * only useful on channels 12, 13 and 14 on the 2 GHz band as channels
+ * 1-11 are already enabled by the world regulatory domain; and on
+ * non-radar 5 GHz channels.
+ *
+ * Drivers do not need to call this, cfg80211 will do it for after a scan
+ * on a newly found BSS.
+ */
+int regulatory_hint_found_beacon(struct wiphy *wiphy,
+                                        struct ieee80211_channel *beacon_chan,
+                                        gfp_t gfp);
+
 #endif  /* __NET_WIRELESS_REG_H */
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 60600657b657..280dbcd02c15 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -430,6 +430,9 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
         if (!res)
                 return NULL;
 
+        if (res->pub.capability & WLAN_CAPABILITY_ESS)
+                regulatory_hint_found_beacon(wiphy, channel, gfp);
+
         /* cfg80211_bss_update gives us a referenced result */
         return &res->pub;
 }