eapol_sm.c

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/*
 * Host AP (software wireless LAN access point) user space daemon for
 * Host AP kernel driver / IEEE 802.1X Authenticator - EAPOL state machine
 * Copyright (c) 2002-2005, Jouni Malinen <[e-mail]>
 *
 * 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 <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
#include <sys/socket.h>

#include "hostapd.h"
#include "ieee802_1x.h"
#include "eapol_sm.h"
#include "eloop.h"
#include "wpa.h"
#include "sta_info.h"
#include "eap.h"

static struct eapol_callbacks eapol_cb;

/* EAPOL state machines are described in IEEE Std 802.1X-REV-d11, Chap. 8.2 */

#define setPortAuthorized() \
ieee802_1x_set_sta_authorized(sm->hapd, sm->sta, 1)
#define setPortUnauthorized() \
ieee802_1x_set_sta_authorized(sm->hapd, sm->sta, 0)

/* procedures */
#define txCannedFail() ieee802_1x_tx_canned_eap(sm->hapd, sm->sta, 0)
#define txCannedSuccess() ieee802_1x_tx_canned_eap(sm->hapd, sm->sta, 1)
#define txReq() ieee802_1x_tx_req(sm->hapd, sm->sta)
#define sendRespToServer() ieee802_1x_send_resp_to_server(sm->hapd, sm->sta)
#define abortAuth() ieee802_1x_abort_auth(sm->hapd, sm->sta)
#define txKey() ieee802_1x_tx_key(sm->hapd, sm->sta)
#define processKey() do { } while (0)


/* Definitions for clarifying state machine implementation */
#define SM_STATE(machine, state) \
static void sm_ ## machine ## _ ## state ## _Enter(struct eapol_state_machine \
*sm)

#define SM_ENTRY(machine, _state, _data) \
sm->_data.state = machine ## _ ## _state; \
if (sm->hapd->conf->debug >= HOSTAPD_DEBUG_MINIMAL) \
	printf("IEEE 802.1X: " MACSTR " " #machine " entering state " #_state \
		"\n", MAC2STR(sm->addr));

#define SM_ENTER(machine, state) sm_ ## machine ## _ ## state ## _Enter(sm)

#define SM_STEP(machine) \
static void sm_ ## machine ## _Step(struct eapol_state_machine *sm)

#define SM_STEP_RUN(machine) sm_ ## machine ## _Step(sm)



/* Port Timers state machine - implemented as a function that will be called
 * once a second as a registered event loop timeout */

static void eapol_port_timers_tick(void *eloop_ctx, void *timeout_ctx)
{
	struct eapol_state_machine *state = timeout_ctx;

	if (state->aWhile > 0)
		state->aWhile--;
	if (state->quietWhile > 0)
		state->quietWhile--;
	if (state->reAuthWhen > 0)
		state->reAuthWhen--;

	if (state->hapd->conf->debug >= HOSTAPD_DEBUG_MSGDUMPS)
		printf("IEEE 802.1X: " MACSTR " Port Timers TICK "
		       "(timers: %d %d %d)\n", MAC2STR(state->addr),
		       state->aWhile, state->quietWhile, state->reAuthWhen);

	eapol_sm_step(state);

	eloop_register_timeout(1, 0, eapol_port_timers_tick, eloop_ctx, state);
}



/* Authenticator PAE state machine */

SM_STATE(AUTH_PAE, INITIALIZE)
{
	SM_ENTRY(AUTH_PAE, INITIALIZE, auth_pae);
	sm->auth_pae.portMode = Auto;

	sm->currentId = 255;
}


SM_STATE(AUTH_PAE, DISCONNECTED)
{
	int from_initialize = sm->auth_pae.state == AUTH_PAE_INITIALIZE;

	if (sm->auth_pae.eapolLogoff) {
		if (sm->auth_pae.state == AUTH_PAE_CONNECTING)
			sm->auth_pae.authEapLogoffsWhileConnecting++;
		else if (sm->auth_pae.state == AUTH_PAE_AUTHENTICATED)
			sm->auth_pae.authAuthEapLogoffWhileAuthenticated++;
	}

	SM_ENTRY(AUTH_PAE, DISCONNECTED, auth_pae);

	sm->authPortStatus = Unauthorized;
	setPortUnauthorized();
	sm->auth_pae.reAuthCount = 0;
	sm->auth_pae.eapolLogoff = FALSE;
	if (!from_initialize) {
		if (sm->flags & EAPOL_SM_PREAUTH)
			rsn_preauth_finished(sm->hapd, sm->sta, 0);
		else
			ieee802_1x_finished(sm->hapd, sm->sta, 0);
	}
}


SM_STATE(AUTH_PAE, RESTART)
{
	if (sm->auth_pae.state == AUTH_PAE_AUTHENTICATED) {
		if (sm->reAuthenticate)
			sm->auth_pae.authAuthReauthsWhileAuthenticated++;
		if (sm->auth_pae.eapolStart)
			sm->auth_pae.authAuthEapStartsWhileAuthenticated++;
		if (sm->auth_pae.eapolLogoff)
			sm->auth_pae.authAuthEapLogoffWhileAuthenticated++;
	}

	SM_ENTRY(AUTH_PAE, RESTART, auth_pae);

	sm->auth_pae.eapRestart = TRUE;
	ieee802_1x_request_identity(sm->hapd, sm->sta);
}


SM_STATE(AUTH_PAE, CONNECTING)
{
	if (sm->auth_pae.state != AUTH_PAE_CONNECTING)
		sm->auth_pae.authEntersConnecting++;

	SM_ENTRY(AUTH_PAE, CONNECTING, auth_pae);

	sm->reAuthenticate = FALSE;
	sm->auth_pae.reAuthCount++;
}


SM_STATE(AUTH_PAE, HELD)
{
	if (sm->auth_pae.state == AUTH_PAE_AUTHENTICATING && sm->authFail)
		sm->auth_pae.authAuthFailWhileAuthenticating++;

	SM_ENTRY(AUTH_PAE, HELD, auth_pae);

	sm->authPortStatus = Unauthorized;
	setPortUnauthorized();
	sm->quietWhile = sm->auth_pae.quietPeriod;
	sm->auth_pae.eapolLogoff = FALSE;

	hostapd_logger(sm->hapd, sm->addr, HOSTAPD_MODULE_IEEE8021X,
		       HOSTAPD_LEVEL_WARNING, "authentication failed");
	if (sm->flags & EAPOL_SM_PREAUTH)
		rsn_preauth_finished(sm->hapd, sm->sta, 0);
	else
		ieee802_1x_finished(sm->hapd, sm->sta, 0);
}


SM_STATE(AUTH_PAE, AUTHENTICATED)
{
	if (sm->auth_pae.state == AUTH_PAE_AUTHENTICATING && sm->authSuccess)
		sm->auth_pae.authAuthSuccessesWhileAuthenticating++;
							
	SM_ENTRY(AUTH_PAE, AUTHENTICATED, auth_pae);

	sm->authPortStatus = Authorized;
	setPortAuthorized();
	sm->auth_pae.reAuthCount = 0;
	hostapd_logger(sm->hapd, sm->addr, HOSTAPD_MODULE_IEEE8021X,
		       HOSTAPD_LEVEL_INFO, "authenticated");
	if (sm->flags & EAPOL_SM_PREAUTH)
		rsn_preauth_finished(sm->hapd, sm->sta, 1);
	else
		ieee802_1x_finished(sm->hapd, sm->sta, 1);
}


SM_STATE(AUTH_PAE, AUTHENTICATING)
{
	if (sm->auth_pae.state == AUTH_PAE_CONNECTING && sm->rx_identity) {
		sm->auth_pae.authEntersAuthenticating++;
		sm->rx_identity = FALSE;
	}

	SM_ENTRY(AUTH_PAE, AUTHENTICATING, auth_pae);

	sm->auth_pae.eapolStart = FALSE;
	sm->authSuccess = FALSE;
	sm->authFail = FALSE;
	sm->authTimeout = FALSE;
	sm->authStart = TRUE;
	sm->keyRun = FALSE;
	sm->keyDone = FALSE;
}


SM_STATE(AUTH_PAE, ABORTING)
{
	if (sm->auth_pae.state == AUTH_PAE_AUTHENTICATING) {
		if (sm->authTimeout)
			sm->auth_pae.authAuthTimeoutsWhileAuthenticating++;
		if (sm->auth_pae.eapolStart)
			sm->auth_pae.authAuthEapStartsWhileAuthenticating++;
		if (sm->auth_pae.eapolLogoff)
			sm->auth_pae.authAuthEapLogoffWhileAuthenticating++;
	}

	SM_ENTRY(AUTH_PAE, ABORTING, auth_pae);

	sm->authAbort = TRUE;
	sm->keyRun = FALSE;
	sm->keyDone = FALSE;
}


SM_STATE(AUTH_PAE, FORCE_AUTH)
{
	SM_ENTRY(AUTH_PAE, FORCE_AUTH, auth_pae);

	sm->authPortStatus = Authorized;
	setPortAuthorized();
	sm->auth_pae.portMode = ForceAuthorized;
	sm->auth_pae.eapolStart = FALSE;
	txCannedSuccess();
}


SM_STATE(AUTH_PAE, FORCE_UNAUTH)
{
	SM_ENTRY(AUTH_PAE, FORCE_UNAUTH, auth_pae);

	sm->authPortStatus = Unauthorized;
	setPortUnauthorized();
	sm->auth_pae.portMode = ForceUnauthorized;
	sm->auth_pae.eapolStart = FALSE;
	txCannedFail();
}


SM_STEP(AUTH_PAE)
{
	if ((sm->portControl == Auto &&
	     sm->auth_pae.portMode != sm->portControl) ||
	    sm->initialize || !sm->portEnabled)
		SM_ENTER(AUTH_PAE, INITIALIZE);
	else if (sm->portControl == ForceAuthorized &&
		 sm->auth_pae.portMode != sm->portControl &&
		 !(sm->initialize || !sm->portEnabled))
		SM_ENTER(AUTH_PAE, FORCE_AUTH);
	else if (sm->portControl == ForceUnauthorized &&
		 sm->auth_pae.portMode != sm->portControl &&
		 !(sm->initialize || !sm->portEnabled))
		SM_ENTER(AUTH_PAE, FORCE_UNAUTH);
	else {
		switch (sm->auth_pae.state) {
		case AUTH_PAE_INITIALIZE:
			SM_ENTER(AUTH_PAE, DISCONNECTED);
			break;
		case AUTH_PAE_DISCONNECTED:
			SM_ENTER(AUTH_PAE, RESTART);
			break;
		case AUTH_PAE_RESTART:
			if (!sm->auth_pae.eapRestart)
				SM_ENTER(AUTH_PAE, CONNECTING);
			break;
		case AUTH_PAE_HELD:
			if (sm->quietWhile == 0)
				SM_ENTER(AUTH_PAE, RESTART);
			break;
		case AUTH_PAE_CONNECTING:
			if (sm->auth_pae.eapolLogoff ||
			    sm->auth_pae.reAuthCount > sm->auth_pae.reAuthMax)
				SM_ENTER(AUTH_PAE, DISCONNECTED);
			else if ((sm->be_auth.eapReq &&
				  sm->auth_pae.reAuthCount <=
				  sm->auth_pae.reAuthMax) ||
				 sm->eapSuccess || sm->eapFail)
				SM_ENTER(AUTH_PAE, AUTHENTICATING);
			break;
		case AUTH_PAE_AUTHENTICATED:
			if (sm->auth_pae.eapolStart || sm->reAuthenticate)
				SM_ENTER(AUTH_PAE, RESTART);
			else if (sm->auth_pae.eapolLogoff || !sm->portValid)
				SM_ENTER(AUTH_PAE, DISCONNECTED);
			break;
		case AUTH_PAE_AUTHENTICATING:
			if (sm->authSuccess && sm->portValid)
				SM_ENTER(AUTH_PAE, AUTHENTICATED);
			else if (sm->authFail ||
				 (sm->keyDone && !sm->portValid))
				SM_ENTER(AUTH_PAE, HELD);
			else if (sm->auth_pae.eapolStart ||
				 sm->auth_pae.eapolLogoff || sm->authTimeout)
				SM_ENTER(AUTH_PAE, ABORTING);
			break;
		case AUTH_PAE_ABORTING:
			if (sm->auth_pae.eapolLogoff && !sm->authAbort)
				SM_ENTER(AUTH_PAE, DISCONNECTED);
			else if (!sm->auth_pae.eapolLogoff && !sm->authAbort)
				SM_ENTER(AUTH_PAE, RESTART);
			break;
		case AUTH_PAE_FORCE_AUTH:
			if (sm->auth_pae.eapolStart)
				SM_ENTER(AUTH_PAE, FORCE_AUTH);
			break;
		case AUTH_PAE_FORCE_UNAUTH:
			if (sm->auth_pae.eapolStart)
				SM_ENTER(AUTH_PAE, FORCE_UNAUTH);
			break;
		}
	}
}



/* Backend Authentication state machine */

SM_STATE(BE_AUTH, INITIALIZE)
{
	SM_ENTRY(BE_AUTH, INITIALIZE, be_auth);

	abortAuth();
	sm->be_auth.eapNoReq = FALSE;
	sm->authAbort = FALSE;
}


SM_STATE(BE_AUTH, REQUEST)
{
	SM_ENTRY(BE_AUTH, REQUEST, be_auth);

	txReq();
	sm->be_auth.eapReq = FALSE;
	sm->be_auth.backendOtherRequestsToSupplicant++;
}


SM_STATE(BE_AUTH, RESPONSE)
{
	SM_ENTRY(BE_AUTH, RESPONSE, be_auth);

	sm->authTimeout = FALSE;
	sm->eapolEap = FALSE;
	sm->be_auth.eapNoReq = FALSE;
	sm->aWhile = sm->be_auth.serverTimeout;
	sm->be_auth.eapResp = TRUE;
	sendRespToServer();
	sm->be_auth.backendResponses++;
}


SM_STATE(BE_AUTH, SUCCESS)
{
	SM_ENTRY(BE_AUTH, SUCCESS, be_auth);

	txReq();
	sm->authSuccess = TRUE;
	sm->keyRun = TRUE;
}


SM_STATE(BE_AUTH, FAIL)
{
	SM_ENTRY(BE_AUTH, FAIL, be_auth);

	/* Note: IEEE 802.1X-REV-d11 has unconditional txReq() here.
	 * txCannelFail() is used as a workaround for the case where
	 * authentication server does not include EAP-Message with
	 * Access-Reject. */
	if (sm->last_eap_radius == NULL)
		txCannedFail();
	else
		txReq();
	sm->authFail = TRUE;
}


SM_STATE(BE_AUTH, TIMEOUT)
{
	SM_ENTRY(BE_AUTH, TIMEOUT, be_auth);

	sm->authTimeout = TRUE;
}


SM_STATE(BE_AUTH, IDLE)
{
	SM_ENTRY(BE_AUTH, IDLE, be_auth);

	sm->authStart = FALSE;
}


SM_STATE(BE_AUTH, IGNORE)
{
	SM_ENTRY(BE_AUTH, IGNORE, be_auth);

	sm->be_auth.eapNoReq = FALSE;
}


SM_STEP(BE_AUTH)
{
	if (sm->portControl != Auto || sm->initialize || sm->authAbort) {
		SM_ENTER(BE_AUTH, INITIALIZE);
		return;
	}

	switch (sm->be_auth.state) {
	case BE_AUTH_INITIALIZE:
		SM_ENTER(BE_AUTH, IDLE);
		break;
	case BE_AUTH_REQUEST:
		if (sm->eapolEap)
			SM_ENTER(BE_AUTH, RESPONSE);
		else if (sm->be_auth.eapReq)
			SM_ENTER(BE_AUTH, REQUEST);
		else if (sm->eapTimeout)
			SM_ENTER(BE_AUTH, TIMEOUT);
		break;
	case BE_AUTH_RESPONSE:
		if (sm->be_auth.eapNoReq)
			SM_ENTER(BE_AUTH, IGNORE);
		if (sm->be_auth.eapReq) {
			sm->be_auth.backendAccessChallenges++;
			SM_ENTER(BE_AUTH, REQUEST);
		} else if (sm->aWhile == 0)
			SM_ENTER(BE_AUTH, TIMEOUT);
		else if (sm->eapFail) {
			sm->be_auth.backendAuthFails++;
			SM_ENTER(BE_AUTH, FAIL);
		} else if (sm->eapSuccess) {
			sm->be_auth.backendAuthSuccesses++;
			SM_ENTER(BE_AUTH, SUCCESS);
		}
		break;
	case BE_AUTH_SUCCESS:
		SM_ENTER(BE_AUTH, IDLE);
		break;
	case BE_AUTH_FAIL:
		SM_ENTER(BE_AUTH, IDLE);
		break;
	case BE_AUTH_TIMEOUT:
		SM_ENTER(BE_AUTH, IDLE);
		break;
	case BE_AUTH_IDLE:
		if (sm->eapFail && sm->authStart)
			SM_ENTER(BE_AUTH, FAIL);
		else if (sm->be_auth.eapReq && sm->authStart)
			SM_ENTER(BE_AUTH, REQUEST);
		else if (sm->eapSuccess && sm->authStart)
			SM_ENTER(BE_AUTH, SUCCESS);
		break;
	case BE_AUTH_IGNORE:
		if (sm->eapolEap)
			SM_ENTER(BE_AUTH, RESPONSE);
		else if (sm->be_auth.eapReq)
			SM_ENTER(BE_AUTH, REQUEST);
		else if (sm->eapTimeout)
			SM_ENTER(BE_AUTH, TIMEOUT);
		break;
	}
}



/* Reauthentication Timer state machine */

SM_STATE(REAUTH_TIMER, INITIALIZE)
{
	SM_ENTRY(REAUTH_TIMER, INITIALIZE, reauth_timer);

	sm->reAuthWhen = sm->reauth_timer.reAuthPeriod;
}


SM_STATE(REAUTH_TIMER, REAUTHENTICATE)
{
	SM_ENTRY(REAUTH_TIMER, REAUTHENTICATE, reauth_timer);

	sm->reAuthenticate = TRUE;
	wpa_sm_event(sm->hapd, sm->sta, WPA_REAUTH_EAPOL);
}


SM_STEP(REAUTH_TIMER)
{
	if (sm->portControl != Auto || sm->initialize ||
	    sm->authPortStatus == Unauthorized ||
	    !sm->reauth_timer.reAuthEnabled) {
		SM_ENTER(REAUTH_TIMER, INITIALIZE);
		return;
	}

	switch (sm->reauth_timer.state) {
	case REAUTH_TIMER_INITIALIZE:
		if (sm->reAuthWhen == 0)
			SM_ENTER(REAUTH_TIMER, REAUTHENTICATE);
		break;
	case REAUTH_TIMER_REAUTHENTICATE:
		SM_ENTER(REAUTH_TIMER, INITIALIZE);
		break;
	}
}



/* Authenticator Key Transmit state machine */

SM_STATE(AUTH_KEY_TX, NO_KEY_TRANSMIT)
{
	SM_ENTRY(AUTH_KEY_TX, NO_KEY_TRANSMIT, auth_key_tx);
}


SM_STATE(AUTH_KEY_TX, KEY_TRANSMIT)
{
	SM_ENTRY(AUTH_KEY_TX, KEY_TRANSMIT, auth_key_tx);

	txKey();
	sm->keyAvailable = FALSE;
	sm->keyDone = TRUE;
}


SM_STEP(AUTH_KEY_TX)
{
	if (sm->initialize || sm->portControl != Auto) {
		SM_ENTER(AUTH_KEY_TX, NO_KEY_TRANSMIT);
		return;
	}

	switch (sm->auth_key_tx.state) {
	case AUTH_KEY_TX_NO_KEY_TRANSMIT:
		if (sm->keyTxEnabled && sm->keyAvailable && sm->keyRun &&
		    !sm->sta->wpa)
			SM_ENTER(AUTH_KEY_TX, KEY_TRANSMIT);
		break;
	case AUTH_KEY_TX_KEY_TRANSMIT:
		if (!sm->keyTxEnabled || !sm->keyRun)
			SM_ENTER(AUTH_KEY_TX, NO_KEY_TRANSMIT);
		else if (sm->keyAvailable)
			SM_ENTER(AUTH_KEY_TX, KEY_TRANSMIT);
		break;
	}
}



/* Key Receive state machine */

SM_STATE(KEY_RX, NO_KEY_RECEIVE)
{
	SM_ENTRY(KEY_RX, NO_KEY_RECEIVE, key_rx);
}


SM_STATE(KEY_RX, KEY_RECEIVE)
{
	SM_ENTRY(KEY_RX, KEY_RECEIVE, key_rx);

	processKey();
	sm->key_rx.rxKey = FALSE;
}


SM_STEP(KEY_RX)
{
	if (sm->initialize || !sm->portEnabled) {
		SM_ENTER(KEY_RX, NO_KEY_RECEIVE);
		return;
	}

	switch (sm->key_rx.state) {
	case KEY_RX_NO_KEY_RECEIVE:
		if (sm->key_rx.rxKey)