To prevent race conditions between kernel state and
user-space application knowledge, it is better to wait for
a new peer to be completely authenticated before telling the
userspace that it is ready to start authorization
(IBSS/RSN).
Use the IBSS_STA event to tell userspace when a station is
authenticated and ready.
It could still be the case that the other node joining the
AD-HOC cell does not implement AUTH messages exchange,
therefore a fallback mechanism will authenticate the peer
after a timeout set for the purpose expires
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxx>
---
net/mac80211/ibss.c | 103 +++++++++++++++++++++++++++++++++++++++---------
net/mac80211/sta_info.h | 2 +
2 files changed, 87 insertions(+), 18 deletions(-)
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 700d0ed..91956e3 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -30,6 +30,7 @@
#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
+#define IEEE80211_IBSS_AUTH_TIMEOUT (HZ / 2)
#define IEEE80211_IBSS_MAX_STA_ENTRIES 128
@@ -273,8 +274,7 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
false);
}
-static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
- bool auth)
+static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
__acquires(RCU)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
@@ -284,32 +284,33 @@ static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
- sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
- /* authorize the station only if the network is not RSN protected. If
- * not wait for the userspace to authorize it */
- if (!sta->sdata->u.ibss.control_port)
- sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
-
rate_control_rate_init(sta);
/* If it fails, maybe we raced another insertion? */
if (sta_info_insert_rcu(sta))
return sta_info_get(sdata, addr);
- if (auth && !sdata->u.ibss.auth_frame_registrations) {
+ if (!sdata->u.ibss.auth_frame_registrations) {
ibss_dbg(sdata,
"TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
sdata->vif.addr, addr, sdata->u.ibss.bssid);
ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
addr, sdata->u.ibss.bssid, NULL, 0, 0);
+ /* store when the AUTH request has been sent so that this
+ * station can eventually be authorise with the fall back
+ * mechanism
+ */
+ sta->last_auth = jiffies;
+ } else {
+ ieee80211_ibss_auth_sta(sta);
}
+
return sta;
}
static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const u8 *addr,
- u32 supp_rates, bool auth)
+ u32 supp_rates)
__acquires(RCU)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
@@ -358,7 +359,23 @@ ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);
- return ieee80211_ibss_finish_sta(sta, auth);
+ return ieee80211_ibss_finish_sta(sta);
+}
+
+static void ieee80211_ibss_auth_sta(struct sta_info *sta)
+{
+ if (sta->sta_state > IEEE80211_STA_NONE)
+ return;
+
+ sta_info_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_move_state(sta, IEEE80211_STA_ASSOC);
+ /* authorize the station only if the network is not RSN protected. If
+ * not wait for the userspace to authorize it
+ */
+ if (!sta->sdata->u.ibss.control_port)
+ sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+
+ cfg80211_ibss_sta(sta->sdata->dev, sta->sta.addr, GFP_KERNEL);
}
static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
@@ -395,13 +412,36 @@ 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);
- if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
+ if (auth_alg != WLAN_AUTH_OPEN)
return;
- sta_info_destroy_addr(sdata, mgmt->sa);
- sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
+ rcu_read_lock();
+ sta = sta_info_get(sdata, mgmt->sa);
rcu_read_unlock();
+ if (auth_transaction == 2) {
+ ibss_dbg(sdata, "Authenticating STA %pM\n", sta->sta.addr);
+ ieee80211_ibss_auth_sta(sta);
+ return;
+ }
+
+ /* drop bogus auth frames (auth_transaction can be only 1 or 2) */
+ if (auth_transaction != 1)
+ return;
+
+ if (sta && sdata->u.ibss.control_port &&
+ sta->sta_state == IEEE80211_STA_AUTHORIZED) {
+ ibss_dbg(sdata, "Resetting STA %pM state for IBSS Encryption\n",
+ sta->sta.addr);
+ sta_info_destroy_addr(sdata, mgmt->sa);
+ sta = NULL;
+ }
+
+ if (!sta) {
+ sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0);
+ 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
@@ -420,6 +460,8 @@ static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
* However, try to reply to authentication attempts if someone
* has actually implemented this.
*/
+ ibss_dbg(sdata, "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=2)\n",
+ sdata->vif.addr, mgmt->sa, sdata->u.ibss.bssid);
ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0);
}
@@ -481,7 +523,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
} else {
rcu_read_unlock();
sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
- mgmt->sa, supp_rates, true);
+ mgmt->sa, supp_rates);
}
}
@@ -592,7 +634,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
ieee80211_sta_join_ibss(sdata, bss);
supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
- supp_rates, true);
+ supp_rates);
rcu_read_unlock();
}
@@ -675,6 +717,29 @@ static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
return active;
}
+static void ieee80211_ibss_auth_expire(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta;
+
+ list_for_each_entry(sta, &local->sta_list, list) {
+ if (sdata != sta->sdata)
+ continue;
+
+ if (sta->sta_state > IEEE80211_STA_NONE)
+ continue;
+
+ if (time_after(jiffies,
+ sta->last_auth + IEEE80211_IBSS_AUTH_TIMEOUT)) {
+ ibss_dbg(sdata,
+ "Authenticating IBSS STA %pM by timeout\n",
+ sta->sta.addr);
+ ieee80211_ibss_auth_sta(sta);
+ }
+ }
+}
+
+
/*
* This function is called with state == IEEE80211_IBSS_MLME_JOINED
*/
@@ -688,6 +753,8 @@ static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
+ ieee80211_ibss_auth_expire(sdata);
+
ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
if (time_before(jiffies, ifibss->last_scan_completed +
@@ -976,7 +1043,7 @@ void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);
- ieee80211_ibss_finish_sta(sta, true);
+ ieee80211_ibss_finish_sta(sta);
rcu_read_unlock();
spin_lock_bh(&ifibss->incomplete_lock);
}
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 1489bca..3c150a4 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -244,6 +244,7 @@ struct sta_ampdu_mlme {
* @rx_bytes: Number of bytes received from this STA
* @wep_weak_iv_count: number of weak WEP IVs received from this station
* @last_rx: time (in jiffies) when last frame was received from this STA
+ * @last_auth: jiffies of last auth packet with seq = 1
* @last_connected: time (in seconds) when a station got connected
* @num_duplicates: number of duplicate frames received from this STA
* @rx_fragments: number of received MPDUs
@@ -324,6 +325,7 @@ struct sta_info {
unsigned long rx_packets, rx_bytes;
unsigned long wep_weak_iv_count;
unsigned long last_rx;
+ unsigned long last_auth;
long last_connected;
unsigned long num_duplicates;
unsigned long rx_fragments;
--
1.8.0
--
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