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>
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.
11 * Alternatively, this software may be distributed under the terms of BSD
14 * See README and COPYING for more details.
17 #include "utils/includes.h"
19 #ifndef CONFIG_NATIVE_WINDOWS
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"
28 #include "ieee802_11.h"
31 #include "ap_config.h"
33 #include "p2p_hostapd.h"
34 #include "ap_drv_ops.h"
40 static u8 ieee802_11_erp_info(struct hostapd_data *hapd)
44 if (hapd->iface->current_mode == NULL ||
45 hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
48 if (hapd->iface->olbc)
49 erp |= ERP_INFO_USE_PROTECTION;
50 if (hapd->iface->num_sta_non_erp > 0) {
51 erp |= ERP_INFO_NON_ERP_PRESENT |
52 ERP_INFO_USE_PROTECTION;
54 if (hapd->iface->num_sta_no_short_preamble > 0 ||
55 hapd->iconf->preamble == LONG_PREAMBLE)
56 erp |= ERP_INFO_BARKER_PREAMBLE_MODE;
62 static u8 * hostapd_eid_ds_params(struct hostapd_data *hapd, u8 *eid)
64 *eid++ = WLAN_EID_DS_PARAMS;
66 *eid++ = hapd->iconf->channel;
71 static u8 * hostapd_eid_erp_info(struct hostapd_data *hapd, u8 *eid)
73 if (hapd->iface->current_mode == NULL ||
74 hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
77 /* Set NonERP_present and use_protection bits if there
78 * are any associated NonERP stations. */
79 /* TODO: use_protection bit can be set to zero even if
80 * there are NonERP stations present. This optimization
81 * might be useful if NonERP stations are "quiet".
82 * See 802.11g/D6 E-1 for recommended practice.
83 * In addition, Non ERP present might be set, if AP detects Non ERP
84 * operation on other APs. */
86 /* Add ERP Information element */
87 *eid++ = WLAN_EID_ERP_INFO;
89 *eid++ = ieee802_11_erp_info(hapd);
95 static u8 * hostapd_eid_country_add(u8 *pos, u8 *end, int chan_spacing,
96 struct hostapd_channel_data *start,
97 struct hostapd_channel_data *prev)
102 /* first channel number */
103 *pos++ = start->chan;
104 /* number of channels */
105 *pos++ = (prev->chan - start->chan) / chan_spacing + 1;
106 /* maximum transmit power level */
107 *pos++ = start->max_tx_power;
113 static u8 * hostapd_eid_country(struct hostapd_data *hapd, u8 *eid,
117 u8 *end = eid + max_len;
119 struct hostapd_hw_modes *mode;
120 struct hostapd_channel_data *start, *prev;
121 int chan_spacing = 1;
123 if (!hapd->iconf->ieee80211d || max_len < 6 ||
124 hapd->iface->current_mode == NULL)
127 *pos++ = WLAN_EID_COUNTRY;
128 pos++; /* length will be set later */
129 os_memcpy(pos, hapd->iconf->country, 3); /* e.g., 'US ' */
132 mode = hapd->iface->current_mode;
133 if (mode->mode == HOSTAPD_MODE_IEEE80211A)
137 for (i = 0; i < mode->num_channels; i++) {
138 struct hostapd_channel_data *chan = &mode->channels[i];
139 if (chan->flag & HOSTAPD_CHAN_DISABLED)
142 prev->chan + chan_spacing == chan->chan &&
143 start->max_tx_power == chan->max_tx_power) {
145 continue; /* can use same entry */
149 pos = hostapd_eid_country_add(pos, end, chan_spacing,
154 /* Start new group */
159 pos = hostapd_eid_country_add(pos, end, chan_spacing,
163 if ((pos - eid) & 1) {
166 *pos++ = 0; /* pad for 16-bit alignment */
169 eid[1] = (pos - eid) - 2;
175 static u8 * hostapd_eid_wpa(struct hostapd_data *hapd, u8 *eid, size_t len)
180 ie = wpa_auth_get_wpa_ie(hapd->wpa_auth, &ielen);
181 if (ie == NULL || ielen > len)
184 os_memcpy(eid, ie, ielen);
189 static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
190 struct sta_info *sta,
191 const struct ieee80211_mgmt *req,
192 int is_p2p, size_t *resp_len)
194 struct ieee80211_mgmt *resp;
198 #define MAX_PROBERESP_LEN 768
199 buflen = MAX_PROBERESP_LEN;
201 if (hapd->wps_probe_resp_ie)
202 buflen += wpabuf_len(hapd->wps_probe_resp_ie);
203 #endif /* CONFIG_WPS */
205 if (hapd->p2p_probe_resp_ie)
206 buflen += wpabuf_len(hapd->p2p_probe_resp_ie);
207 #endif /* CONFIG_P2P */
208 resp = os_zalloc(buflen);
212 epos = ((u8 *) resp) + MAX_PROBERESP_LEN;
214 resp->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
215 WLAN_FC_STYPE_PROBE_RESP);
217 os_memcpy(resp->da, req->sa, ETH_ALEN);
218 os_memcpy(resp->sa, hapd->own_addr, ETH_ALEN);
220 os_memcpy(resp->bssid, hapd->own_addr, ETH_ALEN);
221 resp->u.probe_resp.beacon_int =
222 host_to_le16(hapd->iconf->beacon_int);
224 /* hardware or low-level driver will setup seq_ctrl and timestamp */
225 resp->u.probe_resp.capab_info =
226 host_to_le16(hostapd_own_capab_info(hapd, sta, 1));
228 pos = resp->u.probe_resp.variable;
229 *pos++ = WLAN_EID_SSID;
230 *pos++ = hapd->conf->ssid.ssid_len;
231 os_memcpy(pos, hapd->conf->ssid.ssid, hapd->conf->ssid.ssid_len);
232 pos += hapd->conf->ssid.ssid_len;
234 /* Supported rates */
235 pos = hostapd_eid_supp_rates(hapd, pos);
238 pos = hostapd_eid_ds_params(hapd, pos);
240 pos = hostapd_eid_country(hapd, pos, epos - pos);
242 /* ERP Information element */
243 pos = hostapd_eid_erp_info(hapd, pos);
245 /* Extended supported rates */
246 pos = hostapd_eid_ext_supp_rates(hapd, pos);
249 pos = hostapd_eid_wpa(hapd, pos, epos - pos);
251 #ifdef CONFIG_IEEE80211N
252 pos = hostapd_eid_ht_capabilities(hapd, pos);
253 pos = hostapd_eid_ht_operation(hapd, pos);
254 #endif /* CONFIG_IEEE80211N */
256 pos = hostapd_eid_ext_capab(hapd, pos);
258 pos = hostapd_eid_time_adv(hapd, pos);
259 pos = hostapd_eid_time_zone(hapd, pos);
261 pos = hostapd_eid_interworking(hapd, pos);
262 pos = hostapd_eid_adv_proto(hapd, pos);
263 pos = hostapd_eid_roaming_consortium(hapd, pos);
265 /* Wi-Fi Alliance WMM */
266 pos = hostapd_eid_wmm(hapd, pos);
269 if (hapd->conf->wps_state && hapd->wps_probe_resp_ie) {
270 os_memcpy(pos, wpabuf_head(hapd->wps_probe_resp_ie),
271 wpabuf_len(hapd->wps_probe_resp_ie));
272 pos += wpabuf_len(hapd->wps_probe_resp_ie);
274 #endif /* CONFIG_WPS */
277 if ((hapd->conf->p2p & P2P_ENABLED) && is_p2p &&
278 hapd->p2p_probe_resp_ie) {
279 os_memcpy(pos, wpabuf_head(hapd->p2p_probe_resp_ie),
280 wpabuf_len(hapd->p2p_probe_resp_ie));
281 pos += wpabuf_len(hapd->p2p_probe_resp_ie);
283 #endif /* CONFIG_P2P */
284 #ifdef CONFIG_P2P_MANAGER
285 if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) ==
287 pos = hostapd_eid_p2p_manage(hapd, pos);
288 #endif /* CONFIG_P2P_MANAGER */
290 *resp_len = pos - (u8 *) resp;
295 void handle_probe_req(struct hostapd_data *hapd,
296 const struct ieee80211_mgmt *mgmt, size_t len)
299 struct ieee802_11_elems elems;
302 struct sta_info *sta = NULL;
306 ie = mgmt->u.probe_req.variable;
307 if (len < IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req))
309 ie_len = len - (IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req));
311 for (i = 0; hapd->probereq_cb && i < hapd->num_probereq_cb; i++)
312 if (hapd->probereq_cb[i].cb(hapd->probereq_cb[i].ctx,
313 mgmt->sa, mgmt->da, mgmt->bssid,
317 if (!hapd->iconf->send_probe_response)
320 if (ieee802_11_parse_elems(ie, ie_len, &elems, 0) == ParseFailed) {
321 wpa_printf(MSG_DEBUG, "Could not parse ProbeReq from " MACSTR,
326 if ((!elems.ssid || !elems.supp_rates)) {
327 wpa_printf(MSG_DEBUG, "STA " MACSTR " sent probe request "
328 "without SSID or supported rates element",
334 if (hapd->p2p && elems.wps_ie) {
336 wps = ieee802_11_vendor_ie_concat(ie, ie_len, WPS_DEV_OUI_WFA);
337 if (wps && !p2p_group_match_dev_type(hapd->p2p_group, wps)) {
338 wpa_printf(MSG_MSGDUMP, "P2P: Ignore Probe Request "
339 "due to mismatch with Requested Device "
346 #endif /* CONFIG_P2P */
348 if (hapd->conf->ignore_broadcast_ssid && elems.ssid_len == 0) {
349 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR " for "
350 "broadcast SSID ignored", MAC2STR(mgmt->sa));
354 sta = ap_get_sta(hapd, mgmt->sa);
357 if ((hapd->conf->p2p & P2P_GROUP_OWNER) &&
358 elems.ssid_len == P2P_WILDCARD_SSID_LEN &&
359 os_memcmp(elems.ssid, P2P_WILDCARD_SSID,
360 P2P_WILDCARD_SSID_LEN) == 0) {
361 /* Process P2P Wildcard SSID like Wildcard SSID */
364 #endif /* CONFIG_P2P */
366 if (elems.ssid_len == 0 ||
367 (elems.ssid_len == hapd->conf->ssid.ssid_len &&
368 os_memcmp(elems.ssid, hapd->conf->ssid.ssid, elems.ssid_len) ==
371 sta->ssid_probe = &hapd->conf->ssid;
373 if (!(mgmt->da[0] & 0x01)) {
375 ieee802_11_print_ssid(ssid_txt, elems.ssid,
377 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR
378 " for foreign SSID '%s' (DA " MACSTR ")",
379 MAC2STR(mgmt->sa), ssid_txt,
385 #ifdef CONFIG_INTERWORKING
386 if (elems.interworking && elems.interworking_len >= 1) {
387 u8 ant = elems.interworking[0] & 0x0f;
388 if (ant != INTERWORKING_ANT_WILDCARD &&
389 ant != hapd->conf->access_network_type) {
390 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR
391 " for mismatching ANT %u ignored",
392 MAC2STR(mgmt->sa), ant);
397 if (elems.interworking &&
398 (elems.interworking_len == 7 || elems.interworking_len == 9)) {
400 if (elems.interworking_len == 7)
401 hessid = elems.interworking + 1;
403 hessid = elems.interworking + 1 + 2;
404 if (!is_broadcast_ether_addr(hessid) &&
405 os_memcmp(hessid, hapd->conf->hessid, ETH_ALEN) != 0) {
406 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR
407 " for mismatching HESSID " MACSTR
409 MAC2STR(mgmt->sa), MAC2STR(hessid));
413 #endif /* CONFIG_INTERWORKING */
415 /* TODO: verify that supp_rates contains at least one matching rate
416 * with AP configuration */
418 resp = hostapd_gen_probe_resp(hapd, sta, mgmt, elems.p2p != NULL,
424 * If this is a broadcast probe request, apply no ack policy to avoid
427 noack = !!(elems.ssid_len == 0 && is_broadcast_ether_addr(mgmt->da));
429 if (hostapd_drv_send_mlme(hapd, resp, resp_len, noack) < 0)
430 perror("handle_probe_req: send");
434 wpa_printf(MSG_EXCESSIVE, "STA " MACSTR " sent probe request for %s "
435 "SSID", MAC2STR(mgmt->sa),
436 elems.ssid_len == 0 ? "broadcast" : "our");
440 static u8 * hostapd_probe_resp_offloads(struct hostapd_data *hapd,
443 /* check probe response offloading caps and print warnings */
444 if (!(hapd->iface->drv_flags & WPA_DRIVER_FLAGS_PROBE_RESP_OFFLOAD))
448 if (hapd->conf->wps_state && hapd->wps_probe_resp_ie &&
449 (!(hapd->iface->probe_resp_offloads &
450 (WPA_DRIVER_PROBE_RESP_OFFLOAD_WPS |
451 WPA_DRIVER_PROBE_RESP_OFFLOAD_WPS2))))
452 wpa_printf(MSG_WARNING, "Device is trying to offload WPS "
453 "Probe Response while not supporting this");
454 #endif /* CONFIG_WPS */
457 if ((hapd->conf->p2p & P2P_ENABLED) && hapd->p2p_probe_resp_ie &&
458 !(hapd->iface->probe_resp_offloads &
459 WPA_DRIVER_PROBE_RESP_OFFLOAD_P2P))
460 wpa_printf(MSG_WARNING, "Device is trying to offload P2P "
461 "Probe Response while not supporting this");
462 #endif /* CONFIG_P2P */
464 if (hapd->conf->interworking &&
465 !(hapd->iface->probe_resp_offloads &
466 WPA_DRIVER_PROBE_RESP_OFFLOAD_INTERWORKING))
467 wpa_printf(MSG_WARNING, "Device is trying to offload "
468 "Interworking Probe Response while not supporting "
471 /* Generate a Probe Response template for the non-P2P case */
472 return hostapd_gen_probe_resp(hapd, NULL, NULL, 0, resp_len);
475 #endif /* NEED_AP_MLME */
478 void ieee802_11_set_beacon(struct hostapd_data *hapd)
480 struct ieee80211_mgmt *head = NULL;
482 size_t head_len = 0, tail_len = 0;
485 struct wpa_driver_ap_params params;
486 struct wpabuf *beacon, *proberesp, *assocresp;
490 #endif /* NEED_AP_MLME */
492 hapd->beacon_set_done = 1;
496 #define BEACON_HEAD_BUF_SIZE 256
497 #define BEACON_TAIL_BUF_SIZE 512
498 head = os_zalloc(BEACON_HEAD_BUF_SIZE);
499 tail_len = BEACON_TAIL_BUF_SIZE;
501 if (hapd->conf->wps_state && hapd->wps_beacon_ie)
502 tail_len += wpabuf_len(hapd->wps_beacon_ie);
503 #endif /* CONFIG_WPS */
505 if (hapd->p2p_beacon_ie)
506 tail_len += wpabuf_len(hapd->p2p_beacon_ie);
507 #endif /* CONFIG_P2P */
508 tailpos = tail = os_malloc(tail_len);
509 if (head == NULL || tail == NULL) {
510 wpa_printf(MSG_ERROR, "Failed to set beacon data");
516 head->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
517 WLAN_FC_STYPE_BEACON);
518 head->duration = host_to_le16(0);
519 os_memset(head->da, 0xff, ETH_ALEN);
521 os_memcpy(head->sa, hapd->own_addr, ETH_ALEN);
522 os_memcpy(head->bssid, hapd->own_addr, ETH_ALEN);
523 head->u.beacon.beacon_int =
524 host_to_le16(hapd->iconf->beacon_int);
526 /* hardware or low-level driver will setup seq_ctrl and timestamp */
527 capab_info = hostapd_own_capab_info(hapd, NULL, 0);
528 head->u.beacon.capab_info = host_to_le16(capab_info);
529 pos = &head->u.beacon.variable[0];
532 *pos++ = WLAN_EID_SSID;
533 if (hapd->conf->ignore_broadcast_ssid == 2) {
534 /* clear the data, but keep the correct length of the SSID */
535 *pos++ = hapd->conf->ssid.ssid_len;
536 os_memset(pos, 0, hapd->conf->ssid.ssid_len);
537 pos += hapd->conf->ssid.ssid_len;
538 } else if (hapd->conf->ignore_broadcast_ssid) {
539 *pos++ = 0; /* empty SSID */
541 *pos++ = hapd->conf->ssid.ssid_len;
542 os_memcpy(pos, hapd->conf->ssid.ssid,
543 hapd->conf->ssid.ssid_len);
544 pos += hapd->conf->ssid.ssid_len;
547 /* Supported rates */
548 pos = hostapd_eid_supp_rates(hapd, pos);
551 pos = hostapd_eid_ds_params(hapd, pos);
553 head_len = pos - (u8 *) head;
555 tailpos = hostapd_eid_country(hapd, tailpos,
556 tail + BEACON_TAIL_BUF_SIZE - tailpos);
558 /* ERP Information element */
559 tailpos = hostapd_eid_erp_info(hapd, tailpos);
561 /* Extended supported rates */
562 tailpos = hostapd_eid_ext_supp_rates(hapd, tailpos);
565 tailpos = hostapd_eid_wpa(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE -
568 #ifdef CONFIG_IEEE80211N
569 tailpos = hostapd_eid_ht_capabilities(hapd, tailpos);
570 tailpos = hostapd_eid_ht_operation(hapd, tailpos);
571 #endif /* CONFIG_IEEE80211N */
573 tailpos = hostapd_eid_ext_capab(hapd, tailpos);
576 * TODO: Time Advertisement element should only be included in some
577 * DTIM Beacon frames.
579 tailpos = hostapd_eid_time_adv(hapd, tailpos);
581 tailpos = hostapd_eid_interworking(hapd, tailpos);
582 tailpos = hostapd_eid_adv_proto(hapd, tailpos);
583 tailpos = hostapd_eid_roaming_consortium(hapd, tailpos);
585 /* Wi-Fi Alliance WMM */
586 tailpos = hostapd_eid_wmm(hapd, tailpos);
589 if (hapd->conf->wps_state && hapd->wps_beacon_ie) {
590 os_memcpy(tailpos, wpabuf_head(hapd->wps_beacon_ie),
591 wpabuf_len(hapd->wps_beacon_ie));
592 tailpos += wpabuf_len(hapd->wps_beacon_ie);
594 #endif /* CONFIG_WPS */
597 if ((hapd->conf->p2p & P2P_ENABLED) && hapd->p2p_beacon_ie) {
598 os_memcpy(tailpos, wpabuf_head(hapd->p2p_beacon_ie),
599 wpabuf_len(hapd->p2p_beacon_ie));
600 tailpos += wpabuf_len(hapd->p2p_beacon_ie);
602 #endif /* CONFIG_P2P */
603 #ifdef CONFIG_P2P_MANAGER
604 if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) ==
606 tailpos = hostapd_eid_p2p_manage(hapd, tailpos);
607 #endif /* CONFIG_P2P_MANAGER */
609 tail_len = tailpos > tail ? tailpos - tail : 0;
611 resp = hostapd_probe_resp_offloads(hapd, &resp_len);
612 #endif /* NEED_AP_MLME */
614 os_memset(¶ms, 0, sizeof(params));
615 params.head = (u8 *) head;
616 params.head_len = head_len;
618 params.tail_len = tail_len;
619 params.proberesp = resp;
620 params.proberesp_len = resp_len;
621 params.dtim_period = hapd->conf->dtim_period;
622 params.beacon_int = hapd->iconf->beacon_int;
623 params.basic_rates = hapd->iconf->basic_rates;
624 params.ssid = (u8 *) hapd->conf->ssid.ssid;
625 params.ssid_len = hapd->conf->ssid.ssid_len;
626 params.pairwise_ciphers = hapd->conf->rsn_pairwise ?
627 hapd->conf->rsn_pairwise : hapd->conf->wpa_pairwise;
628 params.group_cipher = hapd->conf->wpa_group;
629 params.key_mgmt_suites = hapd->conf->wpa_key_mgmt;
630 params.auth_algs = hapd->conf->auth_algs;
631 params.wpa_version = hapd->conf->wpa;
632 params.privacy = hapd->conf->ssid.wep.keys_set || hapd->conf->wpa ||
633 (hapd->conf->ieee802_1x &&
634 (hapd->conf->default_wep_key_len ||
635 hapd->conf->individual_wep_key_len));
636 switch (hapd->conf->ignore_broadcast_ssid) {
638 params.hide_ssid = NO_SSID_HIDING;
641 params.hide_ssid = HIDDEN_SSID_ZERO_LEN;
644 params.hide_ssid = HIDDEN_SSID_ZERO_CONTENTS;
647 hostapd_build_ap_extra_ies(hapd, &beacon, &proberesp, &assocresp);
648 params.beacon_ies = beacon;
649 params.proberesp_ies = proberesp;
650 params.assocresp_ies = assocresp;
651 params.isolate = hapd->conf->isolate;
653 params.cts_protect = !!(ieee802_11_erp_info(hapd) &
654 ERP_INFO_USE_PROTECTION);
655 params.preamble = hapd->iface->num_sta_no_short_preamble == 0 &&
656 hapd->iconf->preamble == SHORT_PREAMBLE;
657 if (hapd->iface->current_mode &&
658 hapd->iface->current_mode->mode == HOSTAPD_MODE_IEEE80211G)
659 params.short_slot_time =
660 hapd->iface->num_sta_no_short_slot_time > 0 ? 0 : 1;
662 params.short_slot_time = -1;
663 if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
664 params.ht_opmode = -1;
666 params.ht_opmode = hapd->iface->ht_op_mode;
667 #endif /* NEED_AP_MLME */
668 params.interworking = hapd->conf->interworking;
669 if (hapd->conf->interworking &&
670 !is_zero_ether_addr(hapd->conf->hessid))
671 params.hessid = hapd->conf->hessid;
672 params.access_network_type = hapd->conf->access_network_type;
673 if (hostapd_drv_set_ap(hapd, ¶ms))
674 wpa_printf(MSG_ERROR, "Failed to set beacon parameters");
675 hostapd_free_ap_extra_ies(hapd, beacon, proberesp, assocresp);
683 void ieee802_11_set_beacons(struct hostapd_iface *iface)
686 for (i = 0; i < iface->num_bss; i++)
687 ieee802_11_set_beacon(iface->bss[i]);
690 #endif /* CONFIG_NATIVE_WINDOWS */