mac80211: reply to AUTH with DEAUTH if sta allocation fails in IBSS

Whenever a host gets an AUTH frame it first allocates a new
station and then replies with another AUTH frame. However,
if sta allocations fails the host should send a DEAUTH frame
instead to tell the other end that something went wrong.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
[reword commit message a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index a9d93285dba75b1a9f6ed78fe804f1d1fc20e178..7c082517f0c7b7dda3742b7c4319ac487cc84621 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -332,11 +332,27 @@ ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
        return ieee80211_ibss_finish_sta(sta, auth);
 }
 
+static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
+                                         struct ieee80211_mgmt *mgmt,
+                                         size_t len)
+{
+       u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
+
+       if (len < IEEE80211_DEAUTH_FRAME_LEN)
+               return;
+
+       ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
+                mgmt->sa, mgmt->da, mgmt->bssid, reason);
+       sta_info_destroy_addr(sdata, mgmt->sa);
+}
+
 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
                                        struct ieee80211_mgmt *mgmt,
                                        size_t len)
 {
        u16 auth_alg, auth_transaction;
+       struct sta_info *sta;
+       u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
 
        lockdep_assert_held(&sdata->u.ibss.mtx);
 
@@ -352,9 +368,21 @@ static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
                 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
                 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
        sta_info_destroy_addr(sdata, mgmt->sa);
-       ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
+       sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
        rcu_read_unlock();
 
+       /*
+        * if we have any problem in allocating the new station, we reply with a
+        * DEAUTH frame to tell the other end that we had a problem
+        */
+       if (!sta) {
+               ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
+                                              IEEE80211_STYPE_DEAUTH,
+                                              WLAN_REASON_UNSPECIFIED, true,
+                                              deauth_frame_buf);
+               return;
+       }
+
        /*
         * IEEE 802.11 standard does not require authentication in IBSS
         * networks and most implementations do not seem to use it.
@@ -902,6 +930,9 @@ void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
        case IEEE80211_STYPE_AUTH:
                ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
                break;
+       case IEEE80211_STYPE_DEAUTH:
+               ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
+               break;
        }
 
  mgmt_out: