cfg80211: send regulatory beacon hint events to userspace

This informs userspace when a change has occured on a world
roaming wiphy's channel which has lifted some restrictions
due to a regulatory beacon hint.

Because this is now sent to userspace through the regulatory
multicast group we remove the debug prints we used to use as
they are no longer necessary.

Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 73 insertions, 14 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7285bdc..85b5aa3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3491,6 +3491,60 @@ void nl80211_michael_mic_failure(struct cfg80211_registered_device *rdev,
 	nlmsg_free(msg);
 }
 
+void nl80211_send_beacon_hint_event(struct wiphy *wiphy,
+				    struct ieee80211_channel *channel_before,
+				    struct ieee80211_channel *channel_after)
+{
+	struct sk_buff *msg;
+	void *hdr;
+	struct nlattr *nl_freq;
+
+	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!msg)
+		return;
+
+	hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_REG_BEACON_HINT);
+	if (!hdr) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	/*
+	 * Since we are applying the beacon hint to a wiphy we know its
+	 * wiphy_idx is valid
+	 */
+	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, get_wiphy_idx(wiphy));
+
+	/* Before */
+	nl_freq = nla_nest_start(msg, NL80211_ATTR_FREQ_BEFORE);
+	if (!nl_freq)
+		goto nla_put_failure;
+	if (nl80211_msg_put_channel(msg, channel_before))
+		goto nla_put_failure;
+	nla_nest_end(msg, nl_freq);
+
+	/* After */
+	nl_freq = nla_nest_start(msg, NL80211_ATTR_FREQ_AFTER);
+	if (!nl_freq)
+		goto nla_put_failure;
+	if (nl80211_msg_put_channel(msg, channel_after))
+		goto nla_put_failure;
+	nla_nest_end(msg, nl_freq);
+
+	if (genlmsg_end(msg, hdr) < 0) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	genlmsg_multicast(msg, 0, nl80211_regulatory_mcgrp.id, GFP_ATOMIC);
+
+	return;
+
+nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	nlmsg_free(msg);
+}
+
 /* initialisation/exit functions */
 
 int nl80211_init(void)
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index e4b92cc..b3aaa59 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -29,4 +29,9 @@ nl80211_michael_mic_failure(struct cfg80211_registered_device *rdev,
 			    enum nl80211_key_type key_type,
 			    int key_id, const u8 *tsc);
 
+extern void
+nl80211_send_beacon_hint_event(struct wiphy *wiphy,
+			       struct ieee80211_channel *channel_before,
+			       struct ieee80211_channel *channel_after);
+
 #endif /* __NET_WIRELESS_NL80211_H */
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 4af4304..574e217 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1049,18 +1049,10 @@ 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;
+	bool channel_changed = false;
+	struct ieee80211_channel chan_before;
 
 	assert_cfg80211_lock();
 
@@ -1070,20 +1062,28 @@ static void handle_reg_beacon(struct wiphy *wiphy,
 	if (likely(chan->center_freq != reg_beacon->chan.center_freq))
 		return;
 
+	if (chan->beacon_found)
+		return;
+
+	chan->beacon_found = true;
+
+	chan_before.center_freq = chan->center_freq;
+	chan_before.flags = chan->flags;
+
 	if ((chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) &&
 	    !(chan->orig_flags & IEEE80211_CHAN_PASSIVE_SCAN)) {
 		chan->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
-		REG_DEBUG_BEACON_FLAG("active scanning");
+		channel_changed = true;
 	}
 
 	if ((chan->flags & IEEE80211_CHAN_NO_IBSS) &&
 	    !(chan->orig_flags & IEEE80211_CHAN_NO_IBSS)) {
 		chan->flags &= ~IEEE80211_CHAN_NO_IBSS;
-		REG_DEBUG_BEACON_FLAG("beaconing");
+		channel_changed = true;
 	}
 
-	chan->beacon_found = true;
-#undef REG_DEBUG_BEACON_FLAG
+	if (channel_changed)
+		nl80211_send_beacon_hint_event(wiphy, &chan_before, chan);
 }
 
 /*