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>

1 files changed, 32 insertions, 1 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index a9d93285dba7..7c082517f0c7 100644
--- 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);
 
@@ -352,10 +368,22 @@ 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.
          * However, try to reply to authentication attempts if someone
@@ -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: