sme.c

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/*
 * wpa_supplicant - SME
 * Copyright (c) 2009-2010, 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 "includes.h"

#include "common.h"
#include "common/ieee802_11_defs.h"
#include "common/ieee802_11_common.h"
#include "eapol_supp/eapol_supp_sm.h"
#include "common/wpa_common.h"
#include "rsn_supp/wpa.h"
#include "rsn_supp/pmksa_cache.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "driver_i.h"
#include "wpas_glue.h"
#include "wps_supplicant.h"
#include "notify.h"
#include "blacklist.h"
#include "bss.h"
#include "scan.h"
#include "sme.h"

void sme_authenticate(struct wpa_supplicant *wpa_s,
                      struct wpa_bss *bss, struct wpa_ssid *ssid)
{
        struct wpa_driver_auth_params params;
        struct wpa_ssid *old_ssid;
#ifdef CONFIG_IEEE80211R
        const u8 *ie;
#endif /* CONFIG_IEEE80211R */
#ifdef CONFIG_IEEE80211R
        const u8 *md = NULL;
#endif /* CONFIG_IEEE80211R */
        int i, bssid_changed;

        if (bss == NULL) {
                wpa_printf(MSG_ERROR, "SME: No scan result available for the "
                           "network");
                return;
        }

        wpa_s->current_bss = bss;

        os_memset(&params, 0, sizeof(params));
        wpa_s->reassociate = 0;

        params.freq = bss->freq;
        params.bssid = bss->bssid;
        params.ssid = bss->ssid;
        params.ssid_len = bss->ssid_len;

        if (wpa_s->sme.ssid_len != params.ssid_len ||
            os_memcmp(wpa_s->sme.ssid, params.ssid, params.ssid_len) != 0)
                wpa_s->sme.prev_bssid_set = 0;

        wpa_s->sme.freq = params.freq;
        os_memcpy(wpa_s->sme.ssid, params.ssid, params.ssid_len);
        wpa_s->sme.ssid_len = params.ssid_len;

        params.auth_alg = WPA_AUTH_ALG_OPEN;
#ifdef IEEE8021X_EAPOL
        if (ssid->key_mgmt & WPA_KEY_MGMT_IEEE8021X_NO_WPA) {
                if (ssid->leap) {
                        if (ssid->non_leap == 0)
                                params.auth_alg = WPA_AUTH_ALG_LEAP;
                        else
                                params.auth_alg |= WPA_AUTH_ALG_LEAP;
                }
        }
#endif /* IEEE8021X_EAPOL */
        wpa_printf(MSG_DEBUG, "Automatic auth_alg selection: 0x%x",
                   params.auth_alg);
        if (ssid->auth_alg) {
                params.auth_alg = ssid->auth_alg;
                wpa_printf(MSG_DEBUG, "Overriding auth_alg selection: 0x%x",
                           params.auth_alg);
        }

        for (i = 0; i < NUM_WEP_KEYS; i++) {
                if (ssid->wep_key_len[i])
                        params.wep_key[i] = ssid->wep_key[i];
                params.wep_key_len[i] = ssid->wep_key_len[i];
        }
        params.wep_tx_keyidx = ssid->wep_tx_keyidx;

        bssid_changed = !is_zero_ether_addr(wpa_s->bssid);
        os_memset(wpa_s->bssid, 0, ETH_ALEN);
        os_memcpy(wpa_s->pending_bssid, bss->bssid, ETH_ALEN);
        if (bssid_changed)
                wpas_notify_bssid_changed(wpa_s);

        if ((wpa_bss_get_vendor_ie(bss, WPA_IE_VENDOR_TYPE) ||
             wpa_bss_get_ie(bss, WLAN_EID_RSN)) &&
            (ssid->key_mgmt & (WPA_KEY_MGMT_IEEE8021X | WPA_KEY_MGMT_PSK |
                               WPA_KEY_MGMT_FT_IEEE8021X |
                               WPA_KEY_MGMT_FT_PSK |
                               WPA_KEY_MGMT_IEEE8021X_SHA256 |
                               WPA_KEY_MGMT_PSK_SHA256))) {
                int try_opportunistic;
                try_opportunistic = ssid->proactive_key_caching &&
                        (ssid->proto & WPA_PROTO_RSN);
                if (pmksa_cache_set_current(wpa_s->wpa, NULL, bss->bssid,
                                            wpa_s->current_ssid,
                                            try_opportunistic) == 0)
                        eapol_sm_notify_pmkid_attempt(wpa_s->eapol, 1);
                wpa_s->sme.assoc_req_ie_len = sizeof(wpa_s->sme.assoc_req_ie);
                if (wpa_supplicant_set_suites(wpa_s, bss, ssid,
                                              wpa_s->sme.assoc_req_ie,
                                              &wpa_s->sme.assoc_req_ie_len)) {
                        wpa_printf(MSG_WARNING, "SME: Failed to set WPA key "
                                   "management and encryption suites");
                        return;
                }
        } else if (ssid->key_mgmt &
                   (WPA_KEY_MGMT_PSK | WPA_KEY_MGMT_IEEE8021X |
                    WPA_KEY_MGMT_WPA_NONE | WPA_KEY_MGMT_FT_PSK |
                    WPA_KEY_MGMT_FT_IEEE8021X | WPA_KEY_MGMT_PSK_SHA256 |
                    WPA_KEY_MGMT_IEEE8021X_SHA256)) {
                wpa_s->sme.assoc_req_ie_len = sizeof(wpa_s->sme.assoc_req_ie);
                if (wpa_supplicant_set_suites(wpa_s, NULL, ssid,
                                              wpa_s->sme.assoc_req_ie,
                                              &wpa_s->sme.assoc_req_ie_len)) {
                        wpa_printf(MSG_WARNING, "SME: Failed to set WPA key "
                                   "management and encryption suites (no scan "
                                   "results)");
                        return;
                }
#ifdef CONFIG_WPS
        } else if (ssid->key_mgmt & WPA_KEY_MGMT_WPS) {
                struct wpabuf *wps_ie;
                wps_ie = wps_build_assoc_req_ie(wpas_wps_get_req_type(ssid));
                if (wps_ie && wpabuf_len(wps_ie) <=
                    sizeof(wpa_s->sme.assoc_req_ie)) {
                        wpa_s->sme.assoc_req_ie_len = wpabuf_len(wps_ie);
                        os_memcpy(wpa_s->sme.assoc_req_ie, wpabuf_head(wps_ie),
                                  wpa_s->sme.assoc_req_ie_len);
                } else
                        wpa_s->sme.assoc_req_ie_len = 0;
                wpabuf_free(wps_ie);
                wpa_supplicant_set_non_wpa_policy(wpa_s, ssid);
#endif /* CONFIG_WPS */
        } else {
                wpa_supplicant_set_non_wpa_policy(wpa_s, ssid);
                wpa_s->sme.assoc_req_ie_len = 0;
        }

#ifdef CONFIG_IEEE80211R
        ie = wpa_bss_get_ie(bss, WLAN_EID_MOBILITY_DOMAIN);
        if (ie && ie[1] >= MOBILITY_DOMAIN_ID_LEN)
                md = ie + 2;
        wpa_sm_set_ft_params(wpa_s->wpa, ie, ie ? 2 + ie[1] : 0);
        if (md) {
                /* Prepare for the next transition */
                wpa_ft_prepare_auth_request(wpa_s->wpa, ie);
        }

        if (md && ssid->key_mgmt & (WPA_KEY_MGMT_FT_PSK |
                                    WPA_KEY_MGMT_FT_IEEE8021X)) {
                if (wpa_s->sme.assoc_req_ie_len + 5 <
                    sizeof(wpa_s->sme.assoc_req_ie)) {
                        struct rsn_mdie *mdie;
                        u8 *pos = wpa_s->sme.assoc_req_ie +
                                wpa_s->sme.assoc_req_ie_len;
                        *pos++ = WLAN_EID_MOBILITY_DOMAIN;
                        *pos++ = sizeof(*mdie);
                        mdie = (struct rsn_mdie *) pos;
                        os_memcpy(mdie->mobility_domain, md,
                                  MOBILITY_DOMAIN_ID_LEN);
                        mdie->ft_capab = md[MOBILITY_DOMAIN_ID_LEN];
                        wpa_s->sme.assoc_req_ie_len += 5;
                }

                if (wpa_s->sme.ft_used &&
                    os_memcmp(md, wpa_s->sme.mobility_domain, 2) == 0 &&
                    wpa_sm_has_ptk(wpa_s->wpa)) {
                        wpa_printf(MSG_DEBUG, "SME: Trying to use FT "
                                   "over-the-air");
                        params.auth_alg = WPA_AUTH_ALG_FT;
                        params.ie = wpa_s->sme.ft_ies;
                        params.ie_len = wpa_s->sme.ft_ies_len;
                }
        }
#endif /* CONFIG_IEEE80211R */

#ifdef CONFIG_IEEE80211W
        wpa_s->sme.mfp = ssid->ieee80211w;
        if (ssid->ieee80211w != NO_MGMT_FRAME_PROTECTION) {
                const u8 *rsn = wpa_bss_get_ie(bss, WLAN_EID_RSN);
                struct wpa_ie_data _ie;
                if (rsn && wpa_parse_wpa_ie(rsn, 2 + rsn[1], &_ie) == 0 &&
                    _ie.capabilities &
                    (WPA_CAPABILITY_MFPC | WPA_CAPABILITY_MFPR)) {
                        wpa_printf(MSG_DEBUG, "WPA: Selected AP supports MFP: "
                                   "require MFP");
                        wpa_s->sme.mfp = MGMT_FRAME_PROTECTION_REQUIRED;
                }
        }
#endif /* CONFIG_IEEE80211W */

        wpa_supplicant_cancel_scan(wpa_s);

        wpa_msg(wpa_s, MSG_INFO, "Trying to authenticate with " MACSTR
                " (SSID='%s' freq=%d MHz)", MAC2STR(params.bssid),
                wpa_ssid_txt(params.ssid, params.ssid_len), params.freq);

        wpa_clear_keys(wpa_s, bss->bssid);
        wpa_supplicant_set_state(wpa_s, WPA_AUTHENTICATING);
        old_ssid = wpa_s->current_ssid;
        wpa_s->current_ssid = ssid;
        wpa_supplicant_rsn_supp_set_config(wpa_s, wpa_s->current_ssid);
        wpa_supplicant_initiate_eapol(wpa_s);
        if (old_ssid != wpa_s->current_ssid)
                wpas_notify_network_changed(wpa_s);

        wpa_s->sme.auth_alg = params.auth_alg;
        if (wpa_drv_authenticate(wpa_s, &params) < 0) {
                wpa_msg(wpa_s, MSG_INFO, "Authentication request to the "
                        "driver failed");
                wpa_supplicant_req_scan(wpa_s, 0, 200000);
                return;
        }

        /* TODO: add timeout on authentication */

        /*
         * Association will be started based on the authentication event from
         * the driver.
         */
}


void sme_event_auth(struct wpa_supplicant *wpa_s, union wpa_event_data *data)
{
        struct wpa_ssid *ssid = wpa_s->current_ssid;

        if (ssid == NULL) {
                wpa_printf(MSG_DEBUG, "SME: Ignore authentication event when "
                           "network is not selected");
                return;
        }

        if (wpa_s->wpa_state != WPA_AUTHENTICATING) {
                wpa_printf(MSG_DEBUG, "SME: Ignore authentication event when "
                           "not in authenticating state");
                return;
        }

        if (os_memcmp(wpa_s->pending_bssid, data->auth.peer, ETH_ALEN) != 0) {
                wpa_printf(MSG_DEBUG, "SME: Ignore authentication with "
                           "unexpected peer " MACSTR,
                           MAC2STR(data->auth.peer));
                return;
        }

        wpa_printf(MSG_DEBUG, "SME: Authentication response: peer=" MACSTR
                   " auth_type=%d status_code=%d",
                   MAC2STR(data->auth.peer), data->auth.auth_type,
                   data->auth.status_code);
        wpa_hexdump(MSG_MSGDUMP, "SME: Authentication response IEs",
                    data->auth.ies, data->auth.ies_len);

        if (data->auth.status_code != WLAN_STATUS_SUCCESS) {
                wpa_printf(MSG_DEBUG, "SME: Authentication failed (status "
                           "code %d)", data->auth.status_code);
                return;
        }

#ifdef CONFIG_IEEE80211R
        if (data->auth.auth_type == WLAN_AUTH_FT) {
                union wpa_event_data edata;
                os_memset(&edata, 0, sizeof(edata));
                edata.ft_ies.ies = data->auth.ies;
                edata.ft_ies.ies_len = data->auth.ies_len;
                os_memcpy(edata.ft_ies.target_ap, data->auth.peer, ETH_ALEN);
                wpa_supplicant_event(wpa_s, EVENT_FT_RESPONSE, &edata);
        }
#endif /* CONFIG_IEEE80211R */

        sme_associate(wpa_s, ssid->mode, data->auth.peer,
                      data->auth.auth_type);
}


void sme_associate(struct wpa_supplicant *wpa_s, enum wpas_mode mode,
                   const u8 *bssid, u16 auth_type)
{
        struct wpa_driver_associate_params params;
        struct ieee802_11_elems elems;

        os_memset(&params, 0, sizeof(params));
        params.bssid = bssid;
        params.ssid = wpa_s->sme.ssid;
        params.ssid_len = wpa_s->sme.ssid_len;
        params.freq = wpa_s->sme.freq;
        params.wpa_ie = wpa_s->sme.assoc_req_ie_len ?
                wpa_s->sme.assoc_req_ie : NULL;
        params.wpa_ie_len = wpa_s->sme.assoc_req_ie_len;
#ifdef CONFIG_IEEE80211R
        if (auth_type == WLAN_AUTH_FT && wpa_s->sme.ft_ies) {
                params.wpa_ie = wpa_s->sme.ft_ies;
                params.wpa_ie_len = wpa_s->sme.ft_ies_len;
        }
#endif /* CONFIG_IEEE80211R */
        params.mode = mode;
        params.mgmt_frame_protection = wpa_s->sme.mfp;
        if (wpa_s->sme.prev_bssid_set)
                params.prev_bssid = wpa_s->sme.prev_bssid;

        wpa_msg(wpa_s, MSG_INFO, "Trying to associate with " MACSTR
                " (SSID='%s' freq=%d MHz)", MAC2STR(params.bssid),
                params.ssid ? wpa_ssid_txt(params.ssid, params.ssid_len) : "",
                params.freq);

        wpa_supplicant_set_state(wpa_s, WPA_ASSOCIATING);

        if (params.wpa_ie == NULL ||
            ieee802_11_parse_elems(params.wpa_ie, params.wpa_ie_len, &elems, 0)
            < 0) {
                wpa_printf(MSG_DEBUG, "SME: Could not parse own IEs?!");
                os_memset(&elems, 0, sizeof(elems));
        }
        if (elems.rsn_ie)
                wpa_sm_set_assoc_wpa_ie(wpa_s->wpa, elems.rsn_ie - 2,
                                        elems.rsn_ie_len + 2);
        else if (elems.wpa_ie)
                wpa_sm_set_assoc_wpa_ie(wpa_s->wpa, elems.wpa_ie - 2,
                                        elems.wpa_ie_len + 2);
        else
                wpa_sm_set_assoc_wpa_ie(wpa_s->wpa, NULL, 0);

        if (wpa_drv_associate(wpa_s, &params) < 0) {
                wpa_msg(wpa_s, MSG_INFO, "Association request to the driver "
                        "failed");
                wpa_supplicant_req_scan(wpa_s, 5, 0);
                return;
        }

        /* TODO: add timeout on association */
}


int sme_update_ft_ies(struct wpa_supplicant *wpa_s, const u8 *md,
                      const u8 *ies, size_t ies_len)
{
        if (md == NULL || ies == NULL) {
                wpa_printf(MSG_DEBUG, "SME: Remove mobility domain");
                os_free(wpa_s->sme.ft_ies);
                wpa_s->sme.ft_ies = NULL;
                wpa_s->sme.ft_ies_len = 0;
                wpa_s->sme.ft_used = 0;
                return 0;
        }

        os_memcpy(wpa_s->sme.mobility_domain, md, MOBILITY_DOMAIN_ID_LEN);
        wpa_hexdump(MSG_DEBUG, "SME: FT IEs", ies, ies_len);
        os_free(wpa_s->sme.ft_ies);
        wpa_s->sme.ft_ies = os_malloc(ies_len);
        if (wpa_s->sme.ft_ies == NULL)
                return -1;
        os_memcpy(wpa_s->sme.ft_ies, ies, ies_len);
        wpa_s->sme.ft_ies_len = ies_len;
        return 0;
}


void sme_event_assoc_reject(struct wpa_supplicant *wpa_s,
                            union wpa_event_data *data)
{
        int bssid_changed;
        int timeout = 5000;

        wpa_printf(MSG_DEBUG, "SME: Association with " MACSTR " failed: "
                   "status code %d", MAC2STR(wpa_s->pending_bssid),
                   data->assoc_reject.status_code);

        bssid_changed = !is_zero_ether_addr(wpa_s->bssid);

        /*
         * For now, unconditionally terminate the previous authentication. In
         * theory, this should not be needed, but mac80211 gets quite confused
         * if the authentication is left pending.. Some roaming cases might
         * benefit from using the previous authentication, so this could be
         * optimized in the future.
         */
        if (wpa_drv_deauthenticate(wpa_s, wpa_s->pending_bssid,
                                   WLAN_REASON_DEAUTH_LEAVING) < 0) {
                wpa_msg(wpa_s, MSG_INFO,
                        "Deauth request to the driver failed");
        }
        wpa_s->sme.prev_bssid_set = 0;

        if (wpa_blacklist_add(wpa_s, wpa_s->pending_bssid) == 0) {
                struct wpa_blacklist *b;
                b = wpa_blacklist_get(wpa_s, wpa_s->pending_bssid);
                if (b && b->count < 3) {
                        /*
                         * Speed up next attempt if there could be other APs
                         * that could accept association.
                         */
                        timeout = 100;
                }
        }
        wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
        os_memset(wpa_s->bssid, 0, ETH_ALEN);
        os_memset(wpa_s->pending_bssid, 0, ETH_ALEN);
        if (bssid_changed)
                wpas_notify_bssid_changed(wpa_s);

        /*
         * TODO: if more than one possible AP is available in scan results,
         * could try the other ones before requesting a new scan.
         */
        wpa_supplicant_req_scan(wpa_s, timeout / 1000,
                                1000 * (timeout % 1000));
}


void sme_event_auth_timed_out(struct wpa_supplicant *wpa_s,
                              union wpa_event_data *data)
{
        int timeout = 5000;
        
        wpa_printf(MSG_DEBUG, "SME: Authentication timed out");
        
        if (wpa_blacklist_add(wpa_s, wpa_s->pending_bssid) == 0) {
                struct wpa_blacklist *b;
                b = wpa_blacklist_get(wpa_s, wpa_s->pending_bssid);
                if (b && b->count < 3) {
                        /*
                         * Speed up next attempt if there could be other APs
                         * that could accept association.
                         */
                        timeout = 100;
                }
        }
        wpa_supplicant_req_scan(wpa_s, timeout / 1000,
                                1000 * (timeout % 1000));
}


void sme_event_assoc_timed_out(struct wpa_supplicant *wpa_s,
                               union wpa_event_data *data)
{
        wpa_printf(MSG_DEBUG, "SME: Association timed out");
        wpa_supplicant_mark_disassoc(wpa_s);
        wpa_supplicant_req_scan(wpa_s, 5, 0);
}


void sme_event_disassoc(struct wpa_supplicant *wpa_s,
                        union wpa_event_data *data)
{
        wpa_printf(MSG_DEBUG, "SME: Disassociation event received");
        if (!is_zero_ether_addr(wpa_s->bssid) &&
            !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)) {
                /*
                 * cfg80211/mac80211 can get into somewhat confused state if
                 * the AP only disassociates us and leaves us in authenticated
                 * state. For now, force the state to be cleared to avoid
                 * confusing errors if we try to associate with the AP again.
                 */
                wpa_printf(MSG_DEBUG, "SME: Deauthenticate to clear driver "
                           "state");
                wpa_drv_deauthenticate(wpa_s, wpa_s->bssid,
                                       WLAN_REASON_DEAUTH_LEAVING);
        }
}