mac80211: Add function to get probe request template for current AP

Chipsets with hardware based connection monitoring need to autonomically
send directed probe-request frames to the AP (in the event of beacon loss,
for example.)

For the hardware to be able to do this, it requires a template for the frame
to transmit to the AP, filled in with the BSSID and SSID of the AP, but also
the supported rate IE's.

This patch adds a function to mac80211, which allows the hardware driver to
fetch this template after association, so it can be configured to the hardware.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 46 insertions, 5 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index b80c38689927..59a1d38212fd 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1287,6 +1287,10 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
                              const u8 *ie, size_t ie_len,
                              enum ieee80211_band band, u32 rate_mask,
                              u8 channel);
+struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
+                                          u8 *dst,
+                                          const u8 *ssid, size_t ssid_len,
+                                          const u8 *ie, size_t ie_len);
 void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
                               const u8 *ssid, size_t ssid_len,
                               const u8 *ie, size_t ie_len);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index a3a9421555af..dfc4a316ac1c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1108,6 +1108,30 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
         mutex_unlock(&ifmgd->mtx);
 }
 
+struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
+                                          struct ieee80211_vif *vif)
+{
+        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+        struct sk_buff *skb;
+        const u8 *ssid;
+
+        if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
+                return NULL;
+
+        ASSERT_MGD_MTX(ifmgd);
+
+        if (!ifmgd->associated)
+                return NULL;
+
+        ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
+        skb = ieee80211_build_probe_req(sdata, ifmgd->associated->bssid,
+                                        ssid + 2, ssid[1], NULL, 0);
+
+        return skb;
+}
+EXPORT_SYMBOL(ieee80211_ap_probereq_get);
+
 static void __ieee80211_connection_loss(struct ieee80211_sub_if_data *sdata)
 {
         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index e486286ebf1a..68d0518254dd 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1011,9 +1011,10 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
         return pos - buffer;
 }
 
-void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
-                              const u8 *ssid, size_t ssid_len,
-                              const u8 *ie, size_t ie_len)
+struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
+                                          u8 *dst,
+                                          const u8 *ssid, size_t ssid_len,
+                                          const u8 *ie, size_t ie_len)
 {
         struct ieee80211_local *local = sdata->local;
         struct sk_buff *skb;
@@ -1027,7 +1028,7 @@ void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
         if (!buf) {
                 printk(KERN_DEBUG "%s: failed to allocate temporary IE "
                        "buffer\n", sdata->name);
-                return;
+                return NULL;
         }
 
         chan = ieee80211_frequency_to_channel(
@@ -1050,8 +1051,20 @@ void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
         }
 
         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
-        ieee80211_tx_skb(sdata, skb);
         kfree(buf);
+
+        return skb;
+}
+
+void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
+                              const u8 *ssid, size_t ssid_len,
+                              const u8 *ie, size_t ie_len)
+{
+        struct sk_buff *skb;
+
+        skb = ieee80211_build_probe_req(sdata, dst, ssid, ssid_len, ie, ie_len);
+        if (skb)
+                ieee80211_tx_skb(sdata, skb);
 }
 
 u32 ieee80211_sta_get_rates(struct ieee80211_local *local,