tkip_countermeasures.c

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/*
 * hostapd / TKIP countermeasures
 * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "utils/includes.h"

#include "utils/common.h"
#include "utils/eloop.h"
#include "common/ieee802_11_defs.h"
#include "hostapd.h"
#include "sta_info.h"
#include "ap_mlme.h"
#include "wpa_auth.h"
#include "tkip_countermeasures.h"


static void ieee80211_tkip_countermeasures_stop(void *eloop_ctx,
                                                void *timeout_ctx)
{
        struct hostapd_data *hapd = eloop_ctx;
        hapd->tkip_countermeasures = 0;
        hapd->drv.set_countermeasures(hapd, 0);
        hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
                       HOSTAPD_LEVEL_INFO, "TKIP countermeasures ended");
}


static void ieee80211_tkip_countermeasures_start(struct hostapd_data *hapd)
{
        struct sta_info *sta;

        hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
                       HOSTAPD_LEVEL_INFO, "TKIP countermeasures initiated");

        wpa_auth_countermeasures_start(hapd->wpa_auth);
        hapd->tkip_countermeasures = 1;
        hapd->drv.set_countermeasures(hapd, 1);
        wpa_gtk_rekey(hapd->wpa_auth);
        eloop_cancel_timeout(ieee80211_tkip_countermeasures_stop, hapd, NULL);
        eloop_register_timeout(60, 0, ieee80211_tkip_countermeasures_stop,
                               hapd, NULL);
        for (sta = hapd->sta_list; sta != NULL; sta = sta->next) {
                hapd->drv.sta_deauth(hapd, sta->addr,
                                     WLAN_REASON_MICHAEL_MIC_FAILURE);
                sta->flags &= ~(WLAN_STA_AUTH | WLAN_STA_ASSOC |
                                WLAN_STA_AUTHORIZED);
                hapd->drv.sta_remove(hapd, sta->addr);
        }
}


void michael_mic_failure(struct hostapd_data *hapd, const u8 *addr, int local)
{
        time_t now;

        if (addr && local) {
                struct sta_info *sta = ap_get_sta(hapd, addr);
                if (sta != NULL) {
                        wpa_auth_sta_local_mic_failure_report(sta->wpa_sm);
                        hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
                                       HOSTAPD_LEVEL_INFO,
                                       "Michael MIC failure detected in "
                                       "received frame");
                        mlme_michaelmicfailure_indication(hapd, addr);
                } else {
                        wpa_printf(MSG_DEBUG,
                                   "MLME-MICHAELMICFAILURE.indication "
                                   "for not associated STA (" MACSTR
                                   ") ignored", MAC2STR(addr));
                        return;
                }
        }

        time(&now);
        if (now > hapd->michael_mic_failure + 60) {
                hapd->michael_mic_failures = 1;
        } else {
                hapd->michael_mic_failures++;
                if (hapd->michael_mic_failures > 1)
                        ieee80211_tkip_countermeasures_start(hapd);
        }
        hapd->michael_mic_failure = now;
}