src/ap/beacon.c

   1 /*
   2  * hostapd / IEEE 802.11 Management: Beacon and Probe Request/Response
   3  * Copyright (c) 2002-2004, Instant802 Networks, Inc.
   4  * Copyright (c) 2005-2006, Devicescape Software, Inc.
   5  * Copyright (c) 2008-2009, Jouni Malinen <j@w1.fi>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * Alternatively, this software may be distributed under the terms of BSD
  12  * license.
  13  *
  14  * See README and COPYING for more details.
  15  */
  16
  17 #include "utils/includes.h"
  18
  19 #ifndef CONFIG_NATIVE_WINDOWS
  20
  21 #include "utils/common.h"
  22 #include "common/ieee802_11_defs.h"
  23 #include "common/ieee802_11_common.h"
  24 #include "drivers/driver.h"
  25 #include "wps/wps_defs.h"
  26 #include "p2p/p2p.h"
  27 #include "hostapd.h"
  28 #include "ieee802_11.h"
  29 #include "wpa_auth.h"
  30 #include "wmm.h"
  31 #include "ap_config.h"
  32 #include "sta_info.h"
  33 #include "beacon.h"
  34
  35
  36 static u8 ieee802_11_erp_info(struct hostapd_data *hapd)
  37 {
  38         u8 erp = 0;
  39
  40         if (hapd->iface->current_mode == NULL ||
  41             hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
  42                 return 0;
  43
  44         switch (hapd->iconf->cts_protection_type) {
  45         case CTS_PROTECTION_FORCE_ENABLED:
  46                 erp |= ERP_INFO_NON_ERP_PRESENT | ERP_INFO_USE_PROTECTION;
  47                 break;
  48         case CTS_PROTECTION_FORCE_DISABLED:
  49                 erp = 0;
  50                 break;
  51         case CTS_PROTECTION_AUTOMATIC:
  52                 if (hapd->iface->olbc)
  53                         erp |= ERP_INFO_USE_PROTECTION;
  54                 /* continue */
  55         case CTS_PROTECTION_AUTOMATIC_NO_OLBC:
  56                 if (hapd->iface->num_sta_non_erp > 0) {
  57                         erp |= ERP_INFO_NON_ERP_PRESENT |
  58                                 ERP_INFO_USE_PROTECTION;
  59                 }
  60                 break;
  61         }
  62         if (hapd->iface->num_sta_no_short_preamble > 0 ||
  63             hapd->iconf->preamble == LONG_PREAMBLE)
  64                 erp |= ERP_INFO_BARKER_PREAMBLE_MODE;
  65
  66         return erp;
  67 }
  68
  69
  70 static u8 * hostapd_eid_ds_params(struct hostapd_data *hapd, u8 *eid)
  71 {
  72         *eid++ = WLAN_EID_DS_PARAMS;
  73         *eid++ = 1;
  74         *eid++ = hapd->iconf->channel;
  75         return eid;
  76 }
  77
  78
  79 static u8 * hostapd_eid_erp_info(struct hostapd_data *hapd, u8 *eid)
  80 {
  81         if (hapd->iface->current_mode == NULL ||
  82             hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
  83                 return eid;
  84
  85         /* Set NonERP_present and use_protection bits if there
  86          * are any associated NonERP stations. */
  87         /* TODO: use_protection bit can be set to zero even if
  88          * there are NonERP stations present. This optimization
  89          * might be useful if NonERP stations are "quiet".
  90          * See 802.11g/D6 E-1 for recommended practice.
  91          * In addition, Non ERP present might be set, if AP detects Non ERP
  92          * operation on other APs. */
  93
  94         /* Add ERP Information element */
  95         *eid++ = WLAN_EID_ERP_INFO;
  96         *eid++ = 1;
  97         *eid++ = ieee802_11_erp_info(hapd);
  98
  99         return eid;
 100 }
 101
 102
 103 static u8 * hostapd_eid_country_add(u8 *pos, u8 *end, int chan_spacing,
 104                                     struct hostapd_channel_data *start,
 105                                     struct hostapd_channel_data *prev)
 106 {
 107         if (end - pos < 3)
 108                 return pos;
 109
 110         /* first channel number */
 111         *pos++ = start->chan;
 112         /* number of channels */
 113         *pos++ = (prev->chan - start->chan) / chan_spacing + 1;
 114         /* maximum transmit power level */
 115         *pos++ = start->max_tx_power;
 116
 117         return pos;
 118 }
 119
 120
 121 static u8 * hostapd_eid_country(struct hostapd_data *hapd, u8 *eid,
 122                                 int max_len)
 123 {
 124         u8 *pos = eid;
 125         u8 *end = eid + max_len;
 126         int i;
 127         struct hostapd_hw_modes *mode;
 128         struct hostapd_channel_data *start, *prev;
 129         int chan_spacing = 1;
 130
 131         if (!hapd->iconf->ieee80211d || max_len < 6 ||
 132             hapd->iface->current_mode == NULL)
 133                 return eid;
 134
 135         *pos++ = WLAN_EID_COUNTRY;
 136         pos++; /* length will be set later */
 137         os_memcpy(pos, hapd->iconf->country, 3); /* e.g., 'US ' */
 138         pos += 3;
 139
 140         mode = hapd->iface->current_mode;
 141         if (mode->mode == HOSTAPD_MODE_IEEE80211A)
 142                 chan_spacing = 4;
 143
 144         start = prev = NULL;
 145         for (i = 0; i < mode->num_channels; i++) {
 146                 struct hostapd_channel_data *chan = &mode->channels[i];
 147                 if (chan->flag & HOSTAPD_CHAN_DISABLED)
 148                         continue;
 149                 if (start && prev &&
 150                     prev->chan + chan_spacing == chan->chan &&
 151                     start->max_tx_power == chan->max_tx_power) {
 152                         prev = chan;
 153                         continue; /* can use same entry */
 154                 }
 155
 156                 if (start) {
 157                         pos = hostapd_eid_country_add(pos, end, chan_spacing,
 158                                                       start, prev);
 159                         start = NULL;
 160                 }
 161
 162                 /* Start new group */
 163                 start = prev = chan;
 164         }
 165
 166         if (start) {
 167                 pos = hostapd_eid_country_add(pos, end, chan_spacing,
 168                                               start, prev);
 169         }
 170
 171         if ((pos - eid) & 1) {
 172                 if (end - pos < 1)
 173                         return eid;
 174                 *pos++ = 0; /* pad for 16-bit alignment */
 175         }
 176
 177         eid[1] = (pos - eid) - 2;
 178
 179         return pos;
 180 }
 181
 182
 183 static u8 * hostapd_eid_wpa(struct hostapd_data *hapd, u8 *eid, size_t len,
 184                             struct sta_info *sta)
 185 {
 186         const u8 *ie;
 187         size_t ielen;
 188
 189         ie = wpa_auth_get_wpa_ie(hapd->wpa_auth, &ielen);
 190         if (ie == NULL || ielen > len)
 191                 return eid;
 192
 193         os_memcpy(eid, ie, ielen);
 194         return eid + ielen;
 195 }
 196
 197
 198 #ifdef CONFIG_P2P_MANAGER
 199 u8 * hostapd_eid_p2p_manage(struct hostapd_data *hapd, u8 *eid)
 200 {
 201         u8 bitmap;
 202         *eid++ = WLAN_EID_VENDOR_SPECIFIC;
 203         *eid++ = 4 + 3 + 1;
 204         WPA_PUT_BE24(eid, OUI_WFA);
 205         eid += 3;
 206         *eid++ = P2P_OUI_TYPE;
 207
 208         *eid++ = P2P_ATTR_MANAGEABILITY;
 209         WPA_PUT_LE16(eid, 1);
 210         eid += 2;
 211         bitmap = P2P_MAN_DEVICE_MANAGEMENT;
 212         if (hapd->conf->p2p & P2P_ALLOW_CROSS_CONNECTION)
 213                 bitmap |= P2P_MAN_CROSS_CONNECTION_PERMITTED;
 214         bitmap |= P2P_MAN_COEXISTENCE_OPTIONAL;
 215         *eid++ = bitmap;
 216
 217         return eid;
 218 }
 219 #endif /* CONFIG_P2P_MANAGER */
 220
 221
 222 void handle_probe_req(struct hostapd_data *hapd,
 223                       const struct ieee80211_mgmt *mgmt, size_t len)
 224 {
 225         struct ieee80211_mgmt *resp;
 226         struct ieee802_11_elems elems;
 227         char *ssid;
 228         u8 *pos, *epos;
 229         const u8 *ie;
 230         size_t ssid_len, ie_len;
 231         struct sta_info *sta = NULL;
 232         size_t buflen;
 233         size_t i;
 234
 235         ie = mgmt->u.probe_req.variable;
 236         ie_len = len - (IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req));
 237
 238         for (i = 0; hapd->probereq_cb && i < hapd->num_probereq_cb; i++)
 239                 if (hapd->probereq_cb[i].cb(hapd->probereq_cb[i].ctx,
 240                                             mgmt->sa, ie, ie_len) > 0)
 241                         return;
 242
 243         if (!hapd->iconf->send_probe_response)
 244                 return;
 245
 246         if (ieee802_11_parse_elems(ie, ie_len, &elems, 0) == ParseFailed) {
 247                 wpa_printf(MSG_DEBUG, "Could not parse ProbeReq from " MACSTR,
 248                            MAC2STR(mgmt->sa));
 249                 return;
 250         }
 251
 252         ssid = NULL;
 253         ssid_len = 0;
 254
 255         if ((!elems.ssid || !elems.supp_rates)) {
 256                 wpa_printf(MSG_DEBUG, "STA " MACSTR " sent probe request "
 257                            "without SSID or supported rates element",
 258                            MAC2STR(mgmt->sa));
 259                 return;
 260         }
 261
 262 #ifdef CONFIG_P2P
 263         if (hapd->p2p && elems.wps_ie) {
 264                 struct wpabuf *wps;
 265                 wps = ieee802_11_vendor_ie_concat(ie, ie_len, WPS_DEV_OUI_WFA);
 266                 if (wps && !p2p_group_match_dev_type(hapd->p2p_group, wps)) {
 267                         wpa_printf(MSG_MSGDUMP, "P2P: Ignore Probe Request "
 268                                    "due to mismatch with Requested Device "
 269                                    "Type");
 270                         wpabuf_free(wps);
 271                         return;
 272                 }
 273                 wpabuf_free(wps);
 274         }
 275 #endif /* CONFIG_P2P */
 276
 277         if (hapd->conf->ignore_broadcast_ssid && elems.ssid_len == 0) {
 278                 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR " for "
 279                            "broadcast SSID ignored", MAC2STR(mgmt->sa));
 280                 return;
 281         }
 282
 283         sta = ap_get_sta(hapd, mgmt->sa);
 284
 285 #ifdef CONFIG_P2P
 286         if ((hapd->conf->p2p & P2P_GROUP_OWNER) &&
 287             elems.ssid_len == P2P_WILDCARD_SSID_LEN &&
 288             os_memcmp(elems.ssid, P2P_WILDCARD_SSID,
 289                       P2P_WILDCARD_SSID_LEN) == 0) {
 290                 /* Process P2P Wildcard SSID like Wildcard SSID */
 291                 elems.ssid_len = 0;
 292         }
 293 #endif /* CONFIG_P2P */
 294
 295         if (elems.ssid_len == 0 ||
 296             (elems.ssid_len == hapd->conf->ssid.ssid_len &&
 297              os_memcmp(elems.ssid, hapd->conf->ssid.ssid, elems.ssid_len) ==
 298              0)) {
 299                 ssid = hapd->conf->ssid.ssid;
 300                 ssid_len = hapd->conf->ssid.ssid_len;
 301                 if (sta)
 302                         sta->ssid_probe = &hapd->conf->ssid;
 303         }
 304
 305         if (!ssid) {
 306                 if (!(mgmt->da[0] & 0x01)) {
 307                         char ssid_txt[33];
 308                         ieee802_11_print_ssid(ssid_txt, elems.ssid,
 309                                               elems.ssid_len);
 310                         wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR
 311                                    " for foreign SSID '%s' (DA " MACSTR ")",
 312                                    MAC2STR(mgmt->sa), ssid_txt,
 313                                    MAC2STR(mgmt->da));
 314                 }
 315                 return;
 316         }
 317
 318         /* TODO: verify that supp_rates contains at least one matching rate
 319          * with AP configuration */
 320 #define MAX_PROBERESP_LEN 768
 321         buflen = MAX_PROBERESP_LEN;
 322 #ifdef CONFIG_WPS
 323         if (hapd->wps_probe_resp_ie)
 324                 buflen += wpabuf_len(hapd->wps_probe_resp_ie);
 325 #endif /* CONFIG_WPS */
 326 #ifdef CONFIG_P2P
 327         if (hapd->p2p_probe_resp_ie)
 328                 buflen += wpabuf_len(hapd->p2p_probe_resp_ie);
 329 #endif /* CONFIG_P2P */
 330         resp = os_zalloc(buflen);
 331         if (resp == NULL)
 332                 return;
 333         epos = ((u8 *) resp) + MAX_PROBERESP_LEN;
 334
 335         resp->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 336                                            WLAN_FC_STYPE_PROBE_RESP);
 337         os_memcpy(resp->da, mgmt->sa, ETH_ALEN);
 338         os_memcpy(resp->sa, hapd->own_addr, ETH_ALEN);
 339
 340         os_memcpy(resp->bssid, hapd->own_addr, ETH_ALEN);
 341         resp->u.probe_resp.beacon_int =
 342                 host_to_le16(hapd->iconf->beacon_int);
 343
 344         /* hardware or low-level driver will setup seq_ctrl and timestamp */
 345         resp->u.probe_resp.capab_info =
 346                 host_to_le16(hostapd_own_capab_info(hapd, sta, 1));
 347
 348         pos = resp->u.probe_resp.variable;
 349         *pos++ = WLAN_EID_SSID;
 350         *pos++ = ssid_len;
 351         os_memcpy(pos, ssid, ssid_len);
 352         pos += ssid_len;
 353
 354         /* Supported rates */
 355         pos = hostapd_eid_supp_rates(hapd, pos);
 356
 357         /* DS Params */
 358         pos = hostapd_eid_ds_params(hapd, pos);
 359
 360         pos = hostapd_eid_country(hapd, pos, epos - pos);
 361
 362         /* ERP Information element */
 363         pos = hostapd_eid_erp_info(hapd, pos);
 364
 365         /* Extended supported rates */
 366         pos = hostapd_eid_ext_supp_rates(hapd, pos);
 367
 368         /* RSN, MDIE, WPA */
 369         pos = hostapd_eid_wpa(hapd, pos, epos - pos, sta);
 370
 371 #ifdef CONFIG_IEEE80211N
 372         pos = hostapd_eid_ht_capabilities(hapd, pos);
 373         pos = hostapd_eid_ht_operation(hapd, pos);
 374 #endif /* CONFIG_IEEE80211N */
 375
 376         /* Wi-Fi Alliance WMM */
 377         pos = hostapd_eid_wmm(hapd, pos);
 378
 379 #ifdef CONFIG_WPS
 380         if (hapd->conf->wps_state && hapd->wps_probe_resp_ie) {
 381                 os_memcpy(pos, wpabuf_head(hapd->wps_probe_resp_ie),
 382                           wpabuf_len(hapd->wps_probe_resp_ie));
 383                 pos += wpabuf_len(hapd->wps_probe_resp_ie);
 384         }
 385 #endif /* CONFIG_WPS */
 386
 387 #ifdef CONFIG_P2P
 388         if ((hapd->conf->p2p & P2P_ENABLED) && elems.p2p &&
 389             hapd->p2p_probe_resp_ie) {
 390                 os_memcpy(pos, wpabuf_head(hapd->p2p_probe_resp_ie),
 391                           wpabuf_len(hapd->p2p_probe_resp_ie));
 392                 pos += wpabuf_len(hapd->p2p_probe_resp_ie);
 393         }
 394 #endif /* CONFIG_P2P */
 395 #ifdef CONFIG_P2P_MANAGER
 396         if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) ==
 397             P2P_MANAGE)
 398                 pos = hostapd_eid_p2p_manage(hapd, pos);
 399 #endif /* CONFIG_P2P_MANAGER */
 400
 401         if (hapd->drv.send_mgmt_frame(hapd, resp, pos - (u8 *) resp) < 0)
 402                 perror("handle_probe_req: send");
 403
 404         os_free(resp);
 405
 406         wpa_printf(MSG_EXCESSIVE, "STA " MACSTR " sent probe request for %s "
 407                    "SSID", MAC2STR(mgmt->sa),
 408                    elems.ssid_len == 0 ? "broadcast" : "our");
 409 }
 410
 411
 412 void ieee802_11_set_beacon(struct hostapd_data *hapd)
 413 {
 414         struct ieee80211_mgmt *head;
 415         u8 *pos, *tail, *tailpos;
 416         u16 capab_info;
 417         size_t head_len, tail_len;
 418
 419 #ifdef CONFIG_P2P
 420         if ((hapd->conf->p2p & (P2P_ENABLED | P2P_GROUP_OWNER)) == P2P_ENABLED)
 421                 goto no_beacon;
 422 #endif /* CONFIG_P2P */
 423
 424 #define BEACON_HEAD_BUF_SIZE 256
 425 #define BEACON_TAIL_BUF_SIZE 512
 426         head = os_zalloc(BEACON_HEAD_BUF_SIZE);
 427         tail_len = BEACON_TAIL_BUF_SIZE;
 428 #ifdef CONFIG_WPS
 429         if (hapd->conf->wps_state && hapd->wps_beacon_ie)
 430                 tail_len += wpabuf_len(hapd->wps_beacon_ie);
 431 #endif /* CONFIG_WPS */
 432 #ifdef CONFIG_P2P
 433         if (hapd->p2p_beacon_ie)
 434                 tail_len += wpabuf_len(hapd->p2p_beacon_ie);
 435 #endif /* CONFIG_P2P */
 436         tailpos = tail = os_malloc(tail_len);
 437         if (head == NULL || tail == NULL) {
 438                 wpa_printf(MSG_ERROR, "Failed to set beacon data");
 439                 os_free(head);
 440                 os_free(tail);
 441                 return;
 442         }
 443
 444         head->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 445                                            WLAN_FC_STYPE_BEACON);
 446         head->duration = host_to_le16(0);
 447         os_memset(head->da, 0xff, ETH_ALEN);
 448
 449         os_memcpy(head->sa, hapd->own_addr, ETH_ALEN);
 450         os_memcpy(head->bssid, hapd->own_addr, ETH_ALEN);
 451         head->u.beacon.beacon_int =
 452                 host_to_le16(hapd->iconf->beacon_int);
 453
 454         /* hardware or low-level driver will setup seq_ctrl and timestamp */
 455         capab_info = hostapd_own_capab_info(hapd, NULL, 0);
 456         head->u.beacon.capab_info = host_to_le16(capab_info);
 457         pos = &head->u.beacon.variable[0];
 458
 459         /* SSID */
 460         *pos++ = WLAN_EID_SSID;
 461         if (hapd->conf->ignore_broadcast_ssid == 2) {
 462                 /* clear the data, but keep the correct length of the SSID */
 463                 *pos++ = hapd->conf->ssid.ssid_len;
 464                 os_memset(pos, 0, hapd->conf->ssid.ssid_len);
 465                 pos += hapd->conf->ssid.ssid_len;
 466         } else if (hapd->conf->ignore_broadcast_ssid) {
 467                 *pos++ = 0; /* empty SSID */
 468         } else {
 469                 *pos++ = hapd->conf->ssid.ssid_len;
 470                 os_memcpy(pos, hapd->conf->ssid.ssid,
 471                           hapd->conf->ssid.ssid_len);
 472                 pos += hapd->conf->ssid.ssid_len;
 473         }
 474
 475         /* Supported rates */
 476         pos = hostapd_eid_supp_rates(hapd, pos);
 477
 478         /* DS Params */
 479         pos = hostapd_eid_ds_params(hapd, pos);
 480
 481         head_len = pos - (u8 *) head;
 482
 483         tailpos = hostapd_eid_country(hapd, tailpos,
 484                                       tail + BEACON_TAIL_BUF_SIZE - tailpos);
 485
 486         /* ERP Information element */
 487         tailpos = hostapd_eid_erp_info(hapd, tailpos);
 488
 489         /* Extended supported rates */
 490         tailpos = hostapd_eid_ext_supp_rates(hapd, tailpos);
 491
 492         /* RSN, MDIE, WPA */
 493         tailpos = hostapd_eid_wpa(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE -
 494                                   tailpos, NULL);
 495
 496 #ifdef CONFIG_IEEE80211N
 497         tailpos = hostapd_eid_ht_capabilities(hapd, tailpos);
 498         tailpos = hostapd_eid_ht_operation(hapd, tailpos);
 499 #endif /* CONFIG_IEEE80211N */
 500
 501         /* Wi-Fi Alliance WMM */
 502         tailpos = hostapd_eid_wmm(hapd, tailpos);
 503
 504 #ifdef CONFIG_WPS
 505         if (hapd->conf->wps_state && hapd->wps_beacon_ie) {
 506                 os_memcpy(tailpos, wpabuf_head(hapd->wps_beacon_ie),
 507                           wpabuf_len(hapd->wps_beacon_ie));
 508                 tailpos += wpabuf_len(hapd->wps_beacon_ie);
 509         }
 510 #endif /* CONFIG_WPS */
 511
 512 #ifdef CONFIG_P2P
 513         if ((hapd->conf->p2p & P2P_ENABLED) && hapd->p2p_beacon_ie) {
 514                 os_memcpy(tailpos, wpabuf_head(hapd->p2p_beacon_ie),
 515                           wpabuf_len(hapd->p2p_beacon_ie));
 516                 tailpos += wpabuf_len(hapd->p2p_beacon_ie);
 517         }
 518 #endif /* CONFIG_P2P */
 519 #ifdef CONFIG_P2P_MANAGER
 520         if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) ==
 521             P2P_MANAGE)
 522                 tailpos = hostapd_eid_p2p_manage(hapd, tailpos);
 523 #endif /* CONFIG_P2P_MANAGER */
 524
 525         tail_len = tailpos > tail ? tailpos - tail : 0;
 526
 527         if (hapd->drv.set_beacon(hapd, (u8 *) head, head_len,
 528                                  tail, tail_len, hapd->conf->dtim_period,
 529                                  hapd->iconf->beacon_int))
 530                 wpa_printf(MSG_ERROR, "Failed to set beacon head/tail or DTIM "
 531                            "period");
 532
 533         os_free(tail);
 534         os_free(head);
 535
 536 #ifdef CONFIG_P2P
 537 no_beacon:
 538 #endif /* CONFIG_P2P */
 539         hapd->drv.set_bss_params(hapd, !!(ieee802_11_erp_info(hapd) &
 540                                           ERP_INFO_USE_PROTECTION));
 541 }
 542
 543
 544 void ieee802_11_set_beacons(struct hostapd_iface *iface)
 545 {
 546         size_t i;
 547         for (i = 0; i < iface->num_bss; i++)
 548                 ieee802_11_set_beacon(iface->bss[i]);
 549 }
 550
 551 #endif /* CONFIG_NATIVE_WINDOWS */