mac80211: Drop DS Channel PARAM in directed probe

Do not send DS Channel parameter for directed probe requests
in order to maximize the chance that we get a response.  Some
badly-behaved APs don't respond when this parameter is included.

Signed-off-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 26 insertions, 11 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 090b0ec1e056..25c15cc63319 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1350,10 +1350,12 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 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);
+                                          const u8 *ie, size_t ie_len,
+                                          bool directed);
 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);
+                              const u8 *ie, size_t ie_len,
+                              bool directed);
 
 void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
                                   const size_t supp_rates_len,
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index faca5033f061..0f6052faeb45 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1204,7 +1204,8 @@ static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata)
                 ieee80211_send_nullfunc(sdata->local, sdata, 0);
         } else {
                 ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
-                ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid[1], NULL, 0);
+                ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid[1], NULL, 0,
+                                         true);
         }
 
         ifmgd->probe_send_count++;
@@ -1289,7 +1290,7 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
 
         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);
+                                        ssid + 2, ssid[1], NULL, 0, true);
 
         return skb;
 }
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 6403722da603..e5a6ea4a94ea 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -659,7 +659,8 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
                         sdata, NULL,
                         local->scan_req->ssids[i].ssid,
                         local->scan_req->ssids[i].ssid_len,
-                        local->scan_req->ie, local->scan_req->ie_len);
+                        local->scan_req->ie, local->scan_req->ie_len,
+                        false);
 
         /*
          * After sending probe requests, wait for probe responses
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 05e3fb889d77..652e5695225a 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1018,7 +1018,8 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 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)
+                                          const u8 *ie, size_t ie_len,
+                                          bool directed)
 {
         struct ieee80211_local *local = sdata->local;
         struct sk_buff *skb;
@@ -1035,8 +1036,16 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
                 return NULL;
         }
 
-        chan = ieee80211_frequency_to_channel(
-                local->hw.conf.channel->center_freq);
+        /*
+         * Do not send DS Channel parameter for directed probe requests
+         * in order to maximize the chance that we get a response.  Some
+         * badly-behaved APs don't respond when this parameter is included.
+         */
+        if (directed)
+                chan = 0;
+        else
+                chan = ieee80211_frequency_to_channel(
+                        local->hw.conf.channel->center_freq);
 
         buf_len = ieee80211_build_preq_ies(local, buf, ie, ie_len,
                                            local->hw.conf.channel->band,
@@ -1062,11 +1071,13 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
 
 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)
+                              const u8 *ie, size_t ie_len,
+                              bool directed)
 {
         struct sk_buff *skb;
 
-        skb = ieee80211_build_probe_req(sdata, dst, ssid, ssid_len, ie, ie_len);
+        skb = ieee80211_build_probe_req(sdata, dst, ssid, ssid_len, ie, ie_len,
+                                        directed);
         if (skb)
                 ieee80211_tx_skb(sdata, skb);
 }
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index d2e7f0e86677..edf8583280c9 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -450,7 +450,7 @@ ieee80211_direct_probe(struct ieee80211_work *wk)
          * will not answer to direct packet in unassociated state.
          */
         ieee80211_send_probe_req(sdata, NULL, wk->probe_auth.ssid,
-                                 wk->probe_auth.ssid_len, NULL, 0);
+                                 wk->probe_auth.ssid_len, NULL, 0, true);
 
         wk->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
         run_again(local, wk->timeout);