contrib/hostapd/src/ap/wnm_ap.c

   1 /*
   2  * hostapd - WNM
   3  * Copyright (c) 2011-2013, Qualcomm Atheros, Inc.
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "utils/eloop.h"
  13 #include "common/ieee802_11_defs.h"
  14 #include "ap/hostapd.h"
  15 #include "ap/sta_info.h"
  16 #include "ap/ap_config.h"
  17 #include "ap/ap_drv_ops.h"
  18 #include "ap/wpa_auth.h"
  19 #include "wnm_ap.h"
  20
  21 #define MAX_TFS_IE_LEN  1024
  22
  23
  24 /* get the TFS IE from driver */
  25 static int ieee80211_11_get_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
  26                                    u8 *buf, u16 *buf_len, enum wnm_oper oper)
  27 {
  28         wpa_printf(MSG_DEBUG, "%s: TFS get operation %d", __func__, oper);
  29
  30         return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
  31 }
  32
  33
  34 /* set the TFS IE to driver */
  35 static int ieee80211_11_set_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
  36                                    u8 *buf, u16 *buf_len, enum wnm_oper oper)
  37 {
  38         wpa_printf(MSG_DEBUG, "%s: TFS set operation %d", __func__, oper);
  39
  40         return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
  41 }
  42
  43
  44 /* MLME-SLEEPMODE.response */
  45 static int ieee802_11_send_wnmsleep_resp(struct hostapd_data *hapd,
  46                                          const u8 *addr, u8 dialog_token,
  47                                          u8 action_type, u16 intval)
  48 {
  49         struct ieee80211_mgmt *mgmt;
  50         int res;
  51         size_t len;
  52         size_t gtk_elem_len = 0;
  53         size_t igtk_elem_len = 0;
  54         struct wnm_sleep_element wnmsleep_ie;
  55         u8 *wnmtfs_ie;
  56         u8 wnmsleep_ie_len;
  57         u16 wnmtfs_ie_len;
  58         u8 *pos;
  59         struct sta_info *sta;
  60         enum wnm_oper tfs_oper = action_type == WNM_SLEEP_MODE_ENTER ?
  61                 WNM_SLEEP_TFS_RESP_IE_ADD : WNM_SLEEP_TFS_RESP_IE_NONE;
  62
  63         sta = ap_get_sta(hapd, addr);
  64         if (sta == NULL) {
  65                 wpa_printf(MSG_DEBUG, "%s: station not found", __func__);
  66                 return -EINVAL;
  67         }
  68
  69         /* WNM-Sleep Mode IE */
  70         os_memset(&wnmsleep_ie, 0, sizeof(struct wnm_sleep_element));
  71         wnmsleep_ie_len = sizeof(struct wnm_sleep_element);
  72         wnmsleep_ie.eid = WLAN_EID_WNMSLEEP;
  73         wnmsleep_ie.len = wnmsleep_ie_len - 2;
  74         wnmsleep_ie.action_type = action_type;
  75         wnmsleep_ie.status = WNM_STATUS_SLEEP_ACCEPT;
  76         wnmsleep_ie.intval = host_to_le16(intval);
  77
  78         /* TFS IE(s) */
  79         wnmtfs_ie = os_zalloc(MAX_TFS_IE_LEN);
  80         if (wnmtfs_ie == NULL)
  81                 return -1;
  82         if (ieee80211_11_get_tfs_ie(hapd, addr, wnmtfs_ie, &wnmtfs_ie_len,
  83                                     tfs_oper)) {
  84                 wnmtfs_ie_len = 0;
  85                 os_free(wnmtfs_ie);
  86                 wnmtfs_ie = NULL;
  87         }
  88
  89 #define MAX_GTK_SUBELEM_LEN 45
  90 #define MAX_IGTK_SUBELEM_LEN 26
  91         mgmt = os_zalloc(sizeof(*mgmt) + wnmsleep_ie_len +
  92                          MAX_GTK_SUBELEM_LEN + MAX_IGTK_SUBELEM_LEN);
  93         if (mgmt == NULL) {
  94                 wpa_printf(MSG_DEBUG, "MLME: Failed to allocate buffer for "
  95                            "WNM-Sleep Response action frame");
  96                 return -1;
  97         }
  98         os_memcpy(mgmt->da, addr, ETH_ALEN);
  99         os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
 100         os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
 101         mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 102                                            WLAN_FC_STYPE_ACTION);
 103         mgmt->u.action.category = WLAN_ACTION_WNM;
 104         mgmt->u.action.u.wnm_sleep_resp.action = WNM_SLEEP_MODE_RESP;
 105         mgmt->u.action.u.wnm_sleep_resp.dialogtoken = dialog_token;
 106         pos = (u8 *)mgmt->u.action.u.wnm_sleep_resp.variable;
 107         /* add key data if MFP is enabled */
 108         if (!wpa_auth_uses_mfp(sta->wpa_sm) ||
 109             action_type != WNM_SLEEP_MODE_EXIT) {
 110                 mgmt->u.action.u.wnm_sleep_resp.keydata_len = 0;
 111         } else {
 112                 gtk_elem_len = wpa_wnmsleep_gtk_subelem(sta->wpa_sm, pos);
 113                 pos += gtk_elem_len;
 114                 wpa_printf(MSG_DEBUG, "Pass 4, gtk_len = %d",
 115                            (int) gtk_elem_len);
 116 #ifdef CONFIG_IEEE80211W
 117                 res = wpa_wnmsleep_igtk_subelem(sta->wpa_sm, pos);
 118                 if (res < 0) {
 119                         os_free(wnmtfs_ie);
 120                         os_free(mgmt);
 121                         return -1;
 122                 }
 123                 igtk_elem_len = res;
 124                 pos += igtk_elem_len;
 125                 wpa_printf(MSG_DEBUG, "Pass 4 igtk_len = %d",
 126                            (int) igtk_elem_len);
 127 #endif /* CONFIG_IEEE80211W */
 128
 129                 WPA_PUT_LE16((u8 *)
 130                              &mgmt->u.action.u.wnm_sleep_resp.keydata_len,
 131                              gtk_elem_len + igtk_elem_len);
 132         }
 133         os_memcpy(pos, &wnmsleep_ie, wnmsleep_ie_len);
 134         /* copy TFS IE here */
 135         pos += wnmsleep_ie_len;
 136         if (wnmtfs_ie)
 137                 os_memcpy(pos, wnmtfs_ie, wnmtfs_ie_len);
 138
 139         len = 1 + sizeof(mgmt->u.action.u.wnm_sleep_resp) + gtk_elem_len +
 140                 igtk_elem_len + wnmsleep_ie_len + wnmtfs_ie_len;
 141
 142         /* In driver, response frame should be forced to sent when STA is in
 143          * PS mode */
 144         res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
 145                                       mgmt->da, &mgmt->u.action.category, len);
 146
 147         if (!res) {
 148                 wpa_printf(MSG_DEBUG, "Successfully send WNM-Sleep Response "
 149                            "frame");
 150
 151                 /* when entering wnmsleep
 152                  * 1. pause the node in driver
 153                  * 2. mark the node so that AP won't update GTK/IGTK during
 154                  * WNM Sleep
 155                  */
 156                 if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
 157                     wnmsleep_ie.action_type == WNM_SLEEP_MODE_ENTER) {
 158                         sta->flags |= WLAN_STA_WNM_SLEEP_MODE;
 159                         hostapd_drv_wnm_oper(hapd, WNM_SLEEP_ENTER_CONFIRM,
 160                                              addr, NULL, NULL);
 161                         wpa_set_wnmsleep(sta->wpa_sm, 1);
 162                 }
 163                 /* when exiting wnmsleep
 164                  * 1. unmark the node
 165                  * 2. start GTK/IGTK update if MFP is not used
 166                  * 3. unpause the node in driver
 167                  */
 168                 if ((wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT ||
 169                      wnmsleep_ie.status ==
 170                      WNM_STATUS_SLEEP_EXIT_ACCEPT_GTK_UPDATE) &&
 171                     wnmsleep_ie.action_type == WNM_SLEEP_MODE_EXIT) {
 172                         sta->flags &= ~WLAN_STA_WNM_SLEEP_MODE;
 173                         wpa_set_wnmsleep(sta->wpa_sm, 0);
 174                         hostapd_drv_wnm_oper(hapd, WNM_SLEEP_EXIT_CONFIRM,
 175                                              addr, NULL, NULL);
 176                         if (!wpa_auth_uses_mfp(sta->wpa_sm))
 177                                 wpa_wnmsleep_rekey_gtk(sta->wpa_sm);
 178                 }
 179         } else
 180                 wpa_printf(MSG_DEBUG, "Fail to send WNM-Sleep Response frame");
 181
 182 #undef MAX_GTK_SUBELEM_LEN
 183 #undef MAX_IGTK_SUBELEM_LEN
 184         os_free(wnmtfs_ie);
 185         os_free(mgmt);
 186         return res;
 187 }
 188
 189
 190 static void ieee802_11_rx_wnmsleep_req(struct hostapd_data *hapd,
 191                                        const u8 *addr, const u8 *frm, int len)
 192 {
 193         /* Dialog Token [1] | WNM-Sleep Mode IE | TFS Response IE */
 194         const u8 *pos = frm;
 195         u8 dialog_token;
 196         struct wnm_sleep_element *wnmsleep_ie = NULL;
 197         /* multiple TFS Req IE (assuming consecutive) */
 198         u8 *tfsreq_ie_start = NULL;
 199         u8 *tfsreq_ie_end = NULL;
 200         u16 tfsreq_ie_len = 0;
 201
 202         dialog_token = *pos++;
 203         while (pos + 1 < frm + len) {
 204                 u8 ie_len = pos[1];
 205                 if (pos + 2 + ie_len > frm + len)
 206                         break;
 207                 if (*pos == WLAN_EID_WNMSLEEP)
 208                         wnmsleep_ie = (struct wnm_sleep_element *) pos;
 209                 else if (*pos == WLAN_EID_TFS_REQ) {
 210                         if (!tfsreq_ie_start)
 211                                 tfsreq_ie_start = (u8 *) pos;
 212                         tfsreq_ie_end = (u8 *) pos;
 213                 } else
 214                         wpa_printf(MSG_DEBUG, "WNM: EID %d not recognized",
 215                                    *pos);
 216                 pos += ie_len + 2;
 217         }
 218
 219         if (!wnmsleep_ie) {
 220                 wpa_printf(MSG_DEBUG, "No WNM-Sleep IE found");
 221                 return;
 222         }
 223
 224         if (wnmsleep_ie->action_type == WNM_SLEEP_MODE_ENTER &&
 225             tfsreq_ie_start && tfsreq_ie_end &&
 226             tfsreq_ie_end - tfsreq_ie_start >= 0) {
 227                 tfsreq_ie_len = (tfsreq_ie_end + tfsreq_ie_end[1] + 2) -
 228                         tfsreq_ie_start;
 229                 wpa_printf(MSG_DEBUG, "TFS Req IE(s) found");
 230                 /* pass the TFS Req IE(s) to driver for processing */
 231                 if (ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
 232                                             &tfsreq_ie_len,
 233                                             WNM_SLEEP_TFS_REQ_IE_SET))
 234                         wpa_printf(MSG_DEBUG, "Fail to set TFS Req IE");
 235         }
 236
 237         ieee802_11_send_wnmsleep_resp(hapd, addr, dialog_token,
 238                                       wnmsleep_ie->action_type,
 239                                       le_to_host16(wnmsleep_ie->intval));
 240
 241         if (wnmsleep_ie->action_type == WNM_SLEEP_MODE_EXIT) {
 242                 /* clear the tfs after sending the resp frame */
 243                 ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
 244                                         &tfsreq_ie_len, WNM_SLEEP_TFS_IE_DEL);
 245         }
 246 }
 247
 248
 249 static int ieee802_11_send_bss_trans_mgmt_request(struct hostapd_data *hapd,
 250                                                   const u8 *addr,
 251                                                   u8 dialog_token,
 252                                                   const char *url)
 253 {
 254         struct ieee80211_mgmt *mgmt;
 255         size_t url_len, len;
 256         u8 *pos;
 257         int res;
 258
 259         if (url)
 260                 url_len = os_strlen(url);
 261         else
 262                 url_len = 0;
 263
 264         mgmt = os_zalloc(sizeof(*mgmt) + (url_len ? 1 + url_len : 0));
 265         if (mgmt == NULL)
 266                 return -1;
 267         os_memcpy(mgmt->da, addr, ETH_ALEN);
 268         os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
 269         os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
 270         mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 271                                            WLAN_FC_STYPE_ACTION);
 272         mgmt->u.action.category = WLAN_ACTION_WNM;
 273         mgmt->u.action.u.bss_tm_req.action = WNM_BSS_TRANS_MGMT_REQ;
 274         mgmt->u.action.u.bss_tm_req.dialog_token = dialog_token;
 275         mgmt->u.action.u.bss_tm_req.req_mode = 0;
 276         mgmt->u.action.u.bss_tm_req.disassoc_timer = host_to_le16(0);
 277         mgmt->u.action.u.bss_tm_req.validity_interval = 1;
 278         pos = mgmt->u.action.u.bss_tm_req.variable;
 279         if (url) {
 280                 *pos++ += url_len;
 281                 os_memcpy(pos, url, url_len);
 282                 pos += url_len;
 283         }
 284
 285         wpa_printf(MSG_DEBUG, "WNM: Send BSS Transition Management Request to "
 286                    MACSTR " dialog_token=%u req_mode=0x%x disassoc_timer=%u "
 287                    "validity_interval=%u",
 288                    MAC2STR(addr), dialog_token,
 289                    mgmt->u.action.u.bss_tm_req.req_mode,
 290                    le_to_host16(mgmt->u.action.u.bss_tm_req.disassoc_timer),
 291                    mgmt->u.action.u.bss_tm_req.validity_interval);
 292
 293         len = pos - &mgmt->u.action.category;
 294         res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
 295                                       mgmt->da, &mgmt->u.action.category, len);
 296         os_free(mgmt);
 297         return res;
 298 }
 299
 300
 301 static void ieee802_11_rx_bss_trans_mgmt_query(struct hostapd_data *hapd,
 302                                                const u8 *addr, const u8 *frm,
 303                                                size_t len)
 304 {
 305         u8 dialog_token, reason;
 306         const u8 *pos, *end;
 307
 308         if (len < 2) {
 309                 wpa_printf(MSG_DEBUG, "WNM: Ignore too short BSS Transition Management Query from "
 310                            MACSTR, MAC2STR(addr));
 311                 return;
 312         }
 313
 314         pos = frm;
 315         end = pos + len;
 316         dialog_token = *pos++;
 317         reason = *pos++;
 318
 319         wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Query from "
 320                    MACSTR " dialog_token=%u reason=%u",
 321                    MAC2STR(addr), dialog_token, reason);
 322
 323         wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Candidate List Entries",
 324                     pos, end - pos);
 325
 326         ieee802_11_send_bss_trans_mgmt_request(hapd, addr, dialog_token, NULL);
 327 }
 328
 329
 330 static void ieee802_11_rx_bss_trans_mgmt_resp(struct hostapd_data *hapd,
 331                                               const u8 *addr, const u8 *frm,
 332                                               size_t len)
 333 {
 334         u8 dialog_token, status_code, bss_termination_delay;
 335         const u8 *pos, *end;
 336
 337         if (len < 3) {
 338                 wpa_printf(MSG_DEBUG, "WNM: Ignore too short BSS Transition Management Response from "
 339                            MACSTR, MAC2STR(addr));
 340                 return;
 341         }
 342
 343         pos = frm;
 344         end = pos + len;
 345         dialog_token = *pos++;
 346         status_code = *pos++;
 347         bss_termination_delay = *pos++;
 348
 349         wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Response from "
 350                    MACSTR " dialog_token=%u status_code=%u "
 351                    "bss_termination_delay=%u", MAC2STR(addr), dialog_token,
 352                    status_code, bss_termination_delay);
 353
 354         if (status_code == WNM_BSS_TM_ACCEPT) {
 355                 if (end - pos < ETH_ALEN) {
 356                         wpa_printf(MSG_DEBUG, "WNM: not enough room for Target BSSID field");
 357                         return;
 358                 }
 359                 wpa_printf(MSG_DEBUG, "WNM: Target BSSID: " MACSTR,
 360                            MAC2STR(pos));
 361                 pos += ETH_ALEN;
 362         }
 363
 364         wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Candidate List Entries",
 365                     pos, end - pos);
 366 }
 367
 368
 369 int ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
 370                                 const struct ieee80211_mgmt *mgmt, size_t len)
 371 {
 372         u8 action;
 373         const u8 *payload;
 374         size_t plen;
 375
 376         if (len < IEEE80211_HDRLEN + 2)
 377                 return -1;
 378
 379         payload = &mgmt->u.action.category;
 380         payload++;
 381         action = *payload++;
 382         plen = (((const u8 *) mgmt) + len) - payload;
 383
 384         switch (action) {
 385         case WNM_BSS_TRANS_MGMT_QUERY:
 386                 ieee802_11_rx_bss_trans_mgmt_query(hapd, mgmt->sa, payload,
 387                                                    plen);
 388                 return 0;
 389         case WNM_BSS_TRANS_MGMT_RESP:
 390                 ieee802_11_rx_bss_trans_mgmt_resp(hapd, mgmt->sa, payload,
 391                                                   plen);
 392                 return 0;
 393         case WNM_SLEEP_MODE_REQ:
 394                 ieee802_11_rx_wnmsleep_req(hapd, mgmt->sa, payload, plen);
 395                 return 0;
 396         }
 397
 398         wpa_printf(MSG_DEBUG, "WNM: Unsupported WNM Action %u from " MACSTR,
 399                    action, MAC2STR(mgmt->sa));
 400         return -1;
 401 }
 402
 403
 404 int wnm_send_disassoc_imminent(struct hostapd_data *hapd,
 405                                struct sta_info *sta, int disassoc_timer)
 406 {
 407         u8 buf[1000], *pos;
 408         struct ieee80211_mgmt *mgmt;
 409
 410         os_memset(buf, 0, sizeof(buf));
 411         mgmt = (struct ieee80211_mgmt *) buf;
 412         mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 413                                            WLAN_FC_STYPE_ACTION);
 414         os_memcpy(mgmt->da, sta->addr, ETH_ALEN);
 415         os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
 416         os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
 417         mgmt->u.action.category = WLAN_ACTION_WNM;
 418         mgmt->u.action.u.bss_tm_req.action = WNM_BSS_TRANS_MGMT_REQ;
 419         mgmt->u.action.u.bss_tm_req.dialog_token = 1;
 420         mgmt->u.action.u.bss_tm_req.req_mode =
 421                 WNM_BSS_TM_REQ_DISASSOC_IMMINENT;
 422         mgmt->u.action.u.bss_tm_req.disassoc_timer =
 423                 host_to_le16(disassoc_timer);
 424         mgmt->u.action.u.bss_tm_req.validity_interval = 0;
 425
 426         pos = mgmt->u.action.u.bss_tm_req.variable;
 427
 428         wpa_printf(MSG_DEBUG, "WNM: Send BSS Transition Management Request frame to indicate imminent disassociation (disassoc_timer=%d) to "
 429                    MACSTR, disassoc_timer, MAC2STR(sta->addr));
 430         if (hostapd_drv_send_mlme(hapd, buf, pos - buf, 0) < 0) {
 431                 wpa_printf(MSG_DEBUG, "Failed to send BSS Transition "
 432                            "Management Request frame");
 433                 return -1;
 434         }
 435
 436         return 0;
 437 }
 438
 439
 440 int wnm_send_ess_disassoc_imminent(struct hostapd_data *hapd,
 441                                    struct sta_info *sta, const char *url,
 442                                    int disassoc_timer)
 443 {
 444         u8 buf[1000], *pos;
 445         struct ieee80211_mgmt *mgmt;
 446         size_t url_len;
 447
 448         os_memset(buf, 0, sizeof(buf));
 449         mgmt = (struct ieee80211_mgmt *) buf;
 450         mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 451                                            WLAN_FC_STYPE_ACTION);
 452         os_memcpy(mgmt->da, sta->addr, ETH_ALEN);
 453         os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
 454         os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
 455         mgmt->u.action.category = WLAN_ACTION_WNM;
 456         mgmt->u.action.u.bss_tm_req.action = WNM_BSS_TRANS_MGMT_REQ;
 457         mgmt->u.action.u.bss_tm_req.dialog_token = 1;
 458         mgmt->u.action.u.bss_tm_req.req_mode =
 459                 WNM_BSS_TM_REQ_DISASSOC_IMMINENT |
 460                 WNM_BSS_TM_REQ_ESS_DISASSOC_IMMINENT;
 461         mgmt->u.action.u.bss_tm_req.disassoc_timer =
 462                 host_to_le16(disassoc_timer);
 463         mgmt->u.action.u.bss_tm_req.validity_interval = 0x01;
 464
 465         pos = mgmt->u.action.u.bss_tm_req.variable;
 466
 467         /* Session Information URL */
 468         url_len = os_strlen(url);
 469         if (url_len > 255)
 470                 return -1;
 471         *pos++ = url_len;
 472         os_memcpy(pos, url, url_len);
 473         pos += url_len;
 474
 475         if (hostapd_drv_send_mlme(hapd, buf, pos - buf, 0) < 0) {
 476                 wpa_printf(MSG_DEBUG, "Failed to send BSS Transition "
 477                            "Management Request frame");
 478                 return -1;
 479         }
 480
 481         /* send disassociation frame after time-out */
 482         if (disassoc_timer) {
 483                 int timeout, beacon_int;
 484
 485                 /*
 486                  * Prevent STA from reconnecting using cached PMKSA to force
 487                  * full authentication with the authentication server (which may
 488                  * decide to reject the connection),
 489                  */
 490                 wpa_auth_pmksa_remove(hapd->wpa_auth, sta->addr);
 491
 492                 beacon_int = hapd->iconf->beacon_int;
 493                 if (beacon_int < 1)
 494                         beacon_int = 100; /* best guess */
 495                 /* Calculate timeout in ms based on beacon_int in TU */
 496                 timeout = disassoc_timer * beacon_int * 128 / 125;
 497                 wpa_printf(MSG_DEBUG, "Disassociation timer for " MACSTR
 498                            " set to %d ms", MAC2STR(sta->addr), timeout);
 499
 500                 sta->timeout_next = STA_DISASSOC_FROM_CLI;
 501                 eloop_cancel_timeout(ap_handle_timer, hapd, sta);
 502                 eloop_register_timeout(timeout / 1000,
 503                                        timeout % 1000 * 1000,
 504                                        ap_handle_timer, hapd, sta);
 505         }
 506
 507         return 0;
 508 }