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>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index a7323ec..af7e841 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2509,6 +2509,21 @@ void ieee80211_sta_block_awake(struct ieee80211_hw *hw,
                               struct ieee80211_sta *pubsta, bool block);
 
 /**
+ * ieee80211_ap_probereq_get - retrieve a Probe Request template
+ * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * Creates a Probe Request template which can, for example, be uploaded to
+ * hardware. The template is filled with bssid, ssid and supported rate
+ * information. This function must only be called from within the
+ * .bss_info_changed callback function and only in managed mode. The function
+ * is only useful when the interface is associated, otherwise it will return
+ * NULL.
+ */
+struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
+                                         struct ieee80211_vif *vif);
+
+/**
  * ieee80211_beacon_loss - inform hardware does not receive beacons
  *
  * @vif: &struct ieee80211_vif pointer from the add_interface callback.

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index b80c386..59a1d38 100644 (file)
--- 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 a3a9421..dfc4a31 100644 (file)
--- 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 e486286..68d0518 100644 (file)
--- 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,