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 "p2p_hostapd.h"
34 #include "ap_drv_ops.h"
35 #include "beacon.h"
36
37
ieee802_11_erp_info(struct hostapd_data * hapd)38 static u8 ieee802_11_erp_info(struct hostapd_data *hapd)
39 {
40 u8 erp = 0;
41
42 if (hapd->iface->current_mode == NULL ||
43 hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
44 return 0;
45
46 switch (hapd->iconf->cts_protection_type) {
47 case CTS_PROTECTION_FORCE_ENABLED:
48 erp |= ERP_INFO_NON_ERP_PRESENT | ERP_INFO_USE_PROTECTION;
49 break;
50 case CTS_PROTECTION_FORCE_DISABLED:
51 erp = 0;
52 break;
53 case CTS_PROTECTION_AUTOMATIC:
54 if (hapd->iface->olbc)
55 erp |= ERP_INFO_USE_PROTECTION;
56 /* continue */
57 case CTS_PROTECTION_AUTOMATIC_NO_OLBC:
58 if (hapd->iface->num_sta_non_erp > 0) {
59 erp |= ERP_INFO_NON_ERP_PRESENT |
60 ERP_INFO_USE_PROTECTION;
61 }
62 break;
63 }
64 if (hapd->iface->num_sta_no_short_preamble > 0 ||
65 hapd->iconf->preamble == LONG_PREAMBLE)
66 erp |= ERP_INFO_BARKER_PREAMBLE_MODE;
67
68 return erp;
69 }
70
71
hostapd_eid_ds_params(struct hostapd_data * hapd,u8 * eid)72 static u8 * hostapd_eid_ds_params(struct hostapd_data *hapd, u8 *eid)
73 {
74 *eid++ = WLAN_EID_DS_PARAMS;
75 *eid++ = 1;
76 *eid++ = hapd->iconf->channel;
77 return eid;
78 }
79
80
hostapd_eid_erp_info(struct hostapd_data * hapd,u8 * eid)81 static u8 * hostapd_eid_erp_info(struct hostapd_data *hapd, u8 *eid)
82 {
83 if (hapd->iface->current_mode == NULL ||
84 hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
85 return eid;
86
87 /* Set NonERP_present and use_protection bits if there
88 * are any associated NonERP stations. */
89 /* TODO: use_protection bit can be set to zero even if
90 * there are NonERP stations present. This optimization
91 * might be useful if NonERP stations are "quiet".
92 * See 802.11g/D6 E-1 for recommended practice.
93 * In addition, Non ERP present might be set, if AP detects Non ERP
94 * operation on other APs. */
95
96 /* Add ERP Information element */
97 *eid++ = WLAN_EID_ERP_INFO;
98 *eid++ = 1;
99 *eid++ = ieee802_11_erp_info(hapd);
100
101 return eid;
102 }
103
104
hostapd_eid_country_add(u8 * pos,u8 * end,int chan_spacing,struct hostapd_channel_data * start,struct hostapd_channel_data * prev)105 static u8 * hostapd_eid_country_add(u8 *pos, u8 *end, int chan_spacing,
106 struct hostapd_channel_data *start,
107 struct hostapd_channel_data *prev)
108 {
109 if (end - pos < 3)
110 return pos;
111
112 /* first channel number */
113 *pos++ = start->chan;
114 /* number of channels */
115 *pos++ = (prev->chan - start->chan) / chan_spacing + 1;
116 /* maximum transmit power level */
117 *pos++ = start->max_tx_power;
118
119 return pos;
120 }
121
122
hostapd_eid_country(struct hostapd_data * hapd,u8 * eid,int max_len)123 static u8 * hostapd_eid_country(struct hostapd_data *hapd, u8 *eid,
124 int max_len)
125 {
126 u8 *pos = eid;
127 u8 *end = eid + max_len;
128 int i;
129 struct hostapd_hw_modes *mode;
130 struct hostapd_channel_data *start, *prev;
131 int chan_spacing = 1;
132
133 if (!hapd->iconf->ieee80211d || max_len < 6 ||
134 hapd->iface->current_mode == NULL)
135 return eid;
136
137 *pos++ = WLAN_EID_COUNTRY;
138 pos++; /* length will be set later */
139 os_memcpy(pos, hapd->iconf->country, 3); /* e.g., 'US ' */
140 pos += 3;
141
142 mode = hapd->iface->current_mode;
143 if (mode->mode == HOSTAPD_MODE_IEEE80211A)
144 chan_spacing = 4;
145
146 start = prev = NULL;
147 for (i = 0; i < mode->num_channels; i++) {
148 struct hostapd_channel_data *chan = &mode->channels[i];
149 if (chan->flag & HOSTAPD_CHAN_DISABLED)
150 continue;
151 if (start && prev &&
152 prev->chan + chan_spacing == chan->chan &&
153 start->max_tx_power == chan->max_tx_power) {
154 prev = chan;
155 continue; /* can use same entry */
156 }
157
158 if (start) {
159 pos = hostapd_eid_country_add(pos, end, chan_spacing,
160 start, prev);
161 start = NULL;
162 }
163
164 /* Start new group */
165 start = prev = chan;
166 }
167
168 if (start) {
169 pos = hostapd_eid_country_add(pos, end, chan_spacing,
170 start, prev);
171 }
172
173 if ((pos - eid) & 1) {
174 if (end - pos < 1)
175 return eid;
176 *pos++ = 0; /* pad for 16-bit alignment */
177 }
178
179 eid[1] = (pos - eid) - 2;
180
181 return pos;
182 }
183
184
hostapd_eid_wpa(struct hostapd_data * hapd,u8 * eid,size_t len,struct sta_info * sta)185 static u8 * hostapd_eid_wpa(struct hostapd_data *hapd, u8 *eid, size_t len,
186 struct sta_info *sta)
187 {
188 const u8 *ie;
189 size_t ielen;
190
191 ie = wpa_auth_get_wpa_ie(hapd->wpa_auth, &ielen);
192 if (ie == NULL || ielen > len)
193 return eid;
194
195 os_memcpy(eid, ie, ielen);
196 return eid + ielen;
197 }
198
199
handle_probe_req(struct hostapd_data * hapd,const struct ieee80211_mgmt * mgmt,size_t len)200 void handle_probe_req(struct hostapd_data *hapd,
201 const struct ieee80211_mgmt *mgmt, size_t len)
202 {
203 struct ieee80211_mgmt *resp;
204 struct ieee802_11_elems elems;
205 char *ssid;
206 u8 *pos, *epos;
207 const u8 *ie;
208 size_t ssid_len, ie_len;
209 struct sta_info *sta = NULL;
210 size_t buflen;
211 size_t i;
212
213 ie = mgmt->u.probe_req.variable;
214 if (len < IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req))
215 return;
216 ie_len = len - (IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req));
217
218 #ifndef ANDROID_BRCM_P2P_PATCH
219 for (i = 0; hapd->probereq_cb && i < hapd->num_probereq_cb; i++)
220 if (hapd->probereq_cb[i].cb(hapd->probereq_cb[i].ctx,
221 mgmt->sa, ie, ie_len) > 0)
222 return;
223 #endif
224 if (!hapd->iconf->send_probe_response)
225 return;
226
227 if (ieee802_11_parse_elems(ie, ie_len, &elems, 0) == ParseFailed) {
228 wpa_printf(MSG_DEBUG, "Could not parse ProbeReq from " MACSTR,
229 MAC2STR(mgmt->sa));
230 return;
231 }
232
233 ssid = NULL;
234 ssid_len = 0;
235
236 if ((!elems.ssid || !elems.supp_rates)) {
237 wpa_printf(MSG_DEBUG, "STA " MACSTR " sent probe request "
238 "without SSID or supported rates element",
239 MAC2STR(mgmt->sa));
240 return;
241 }
242
243 #ifdef CONFIG_P2P
244 if (hapd->p2p && elems.wps_ie) {
245 struct wpabuf *wps;
246 wps = ieee802_11_vendor_ie_concat(ie, ie_len, WPS_DEV_OUI_WFA);
247 if (wps && !p2p_group_match_dev_type(hapd->p2p_group, wps)) {
248 wpa_printf(MSG_MSGDUMP, "P2P: Ignore Probe Request "
249 "due to mismatch with Requested Device "
250 "Type");
251 wpabuf_free(wps);
252 return;
253 }
254 wpabuf_free(wps);
255 }
256 #endif /* CONFIG_P2P */
257
258 if (hapd->conf->ignore_broadcast_ssid && elems.ssid_len == 0) {
259 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR " for "
260 "broadcast SSID ignored", MAC2STR(mgmt->sa));
261 return;
262 }
263
264 sta = ap_get_sta(hapd, mgmt->sa);
265
266 #ifdef CONFIG_P2P
267 if ((hapd->conf->p2p & P2P_GROUP_OWNER) &&
268 elems.ssid_len == P2P_WILDCARD_SSID_LEN &&
269 os_memcmp(elems.ssid, P2P_WILDCARD_SSID,
270 P2P_WILDCARD_SSID_LEN) == 0) {
271 /* Process P2P Wildcard SSID like Wildcard SSID */
272 elems.ssid_len = 0;
273 }
274 #endif /* CONFIG_P2P */
275
276 if (elems.ssid_len == 0 ||
277 (elems.ssid_len == hapd->conf->ssid.ssid_len &&
278 os_memcmp(elems.ssid, hapd->conf->ssid.ssid, elems.ssid_len) ==
279 0)) {
280 ssid = hapd->conf->ssid.ssid;
281 ssid_len = hapd->conf->ssid.ssid_len;
282 if (sta)
283 sta->ssid_probe = &hapd->conf->ssid;
284 }
285
286 if (!ssid) {
287 if (!(mgmt->da[0] & 0x01)) {
288 char ssid_txt[33];
289 ieee802_11_print_ssid(ssid_txt, elems.ssid,
290 elems.ssid_len);
291 wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR
292 " for foreign SSID '%s' (DA " MACSTR ")",
293 MAC2STR(mgmt->sa), ssid_txt,
294 MAC2STR(mgmt->da));
295 }
296 return;
297 }
298
299 /* TODO: verify that supp_rates contains at least one matching rate
300 * with AP configuration */
301 #define MAX_PROBERESP_LEN 768
302 buflen = MAX_PROBERESP_LEN;
303 #ifdef CONFIG_WPS
304 if (hapd->wps_probe_resp_ie)
305 buflen += wpabuf_len(hapd->wps_probe_resp_ie);
306 #endif /* CONFIG_WPS */
307 #ifdef CONFIG_P2P
308 if (hapd->p2p_probe_resp_ie)
309 buflen += wpabuf_len(hapd->p2p_probe_resp_ie);
310 #endif /* CONFIG_P2P */
311 resp = os_zalloc(buflen);
312 if (resp == NULL)
313 return;
314 epos = ((u8 *) resp) + MAX_PROBERESP_LEN;
315
316 resp->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
317 WLAN_FC_STYPE_PROBE_RESP);
318 os_memcpy(resp->da, mgmt->sa, ETH_ALEN);
319 os_memcpy(resp->sa, hapd->own_addr, ETH_ALEN);
320
321 os_memcpy(resp->bssid, hapd->own_addr, ETH_ALEN);
322 resp->u.probe_resp.beacon_int =
323 host_to_le16(hapd->iconf->beacon_int);
324
325 /* hardware or low-level driver will setup seq_ctrl and timestamp */
326 resp->u.probe_resp.capab_info =
327 host_to_le16(hostapd_own_capab_info(hapd, sta, 1));
328
329 pos = resp->u.probe_resp.variable;
330 *pos++ = WLAN_EID_SSID;
331 *pos++ = ssid_len;
332 os_memcpy(pos, ssid, ssid_len);
333 pos += ssid_len;
334
335 /* Supported rates */
336 pos = hostapd_eid_supp_rates(hapd, pos);
337
338 /* DS Params */
339 pos = hostapd_eid_ds_params(hapd, pos);
340
341 pos = hostapd_eid_country(hapd, pos, epos - pos);
342
343 /* ERP Information element */
344 pos = hostapd_eid_erp_info(hapd, pos);
345
346 /* Extended supported rates */
347 pos = hostapd_eid_ext_supp_rates(hapd, pos);
348
349 /* RSN, MDIE, WPA */
350 pos = hostapd_eid_wpa(hapd, pos, epos - pos, sta);
351
352 #ifdef CONFIG_IEEE80211N
353 pos = hostapd_eid_ht_capabilities(hapd, pos);
354 pos = hostapd_eid_ht_operation(hapd, pos);
355 #endif /* CONFIG_IEEE80211N */
356
357 pos = hostapd_eid_ext_capab(hapd, pos);
358
359 /* Wi-Fi Alliance WMM */
360 pos = hostapd_eid_wmm(hapd, pos);
361
362 #ifdef CONFIG_WPS
363 if (hapd->conf->wps_state && hapd->wps_probe_resp_ie) {
364 os_memcpy(pos, wpabuf_head(hapd->wps_probe_resp_ie),
365 wpabuf_len(hapd->wps_probe_resp_ie));
366 pos += wpabuf_len(hapd->wps_probe_resp_ie);
367 }
368 #endif /* CONFIG_WPS */
369
370 #ifdef CONFIG_P2P
371 if ((hapd->conf->p2p & P2P_ENABLED) && elems.p2p &&
372 hapd->p2p_probe_resp_ie) {
373 os_memcpy(pos, wpabuf_head(hapd->p2p_probe_resp_ie),
374 wpabuf_len(hapd->p2p_probe_resp_ie));
375 pos += wpabuf_len(hapd->p2p_probe_resp_ie);
376 }
377 #endif /* CONFIG_P2P */
378 #ifdef CONFIG_P2P_MANAGER
379 if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) ==
380 P2P_MANAGE)
381 pos = hostapd_eid_p2p_manage(hapd, pos);
382 #endif /* CONFIG_P2P_MANAGER */
383
384 if (hostapd_drv_send_mlme(hapd, resp, pos - (u8 *) resp) < 0)
385 perror("handle_probe_req: send");
386
387 os_free(resp);
388
389 wpa_printf(MSG_EXCESSIVE, "STA " MACSTR " sent probe request for %s "
390 "SSID", MAC2STR(mgmt->sa),
391 elems.ssid_len == 0 ? "broadcast" : "our");
392 }
393
394
ieee802_11_set_beacon(struct hostapd_data * hapd)395 void ieee802_11_set_beacon(struct hostapd_data *hapd)
396 {
397 struct ieee80211_mgmt *head;
398 u8 *pos, *tail, *tailpos;
399 u16 capab_info;
400 size_t head_len, tail_len;
401
402 #ifdef CONFIG_P2P
403 if ((hapd->conf->p2p & (P2P_ENABLED | P2P_GROUP_OWNER)) == P2P_ENABLED)
404 goto no_beacon;
405 #endif /* CONFIG_P2P */
406
407 #define BEACON_HEAD_BUF_SIZE 256
408 #define BEACON_TAIL_BUF_SIZE 512
409 head = os_zalloc(BEACON_HEAD_BUF_SIZE);
410 tail_len = BEACON_TAIL_BUF_SIZE;
411 #ifdef CONFIG_WPS
412 if (hapd->conf->wps_state && hapd->wps_beacon_ie)
413 tail_len += wpabuf_len(hapd->wps_beacon_ie);
414 #endif /* CONFIG_WPS */
415 #ifdef CONFIG_P2P
416 if (hapd->p2p_beacon_ie)
417 tail_len += wpabuf_len(hapd->p2p_beacon_ie);
418 #endif /* CONFIG_P2P */
419 tailpos = tail = os_malloc(tail_len);
420 if (head == NULL || tail == NULL) {
421 wpa_printf(MSG_ERROR, "Failed to set beacon data");
422 os_free(head);
423 os_free(tail);
424 return;
425 }
426
427 head->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
428 WLAN_FC_STYPE_BEACON);
429 head->duration = host_to_le16(0);
430 os_memset(head->da, 0xff, ETH_ALEN);
431
432 os_memcpy(head->sa, hapd->own_addr, ETH_ALEN);
433 os_memcpy(head->bssid, hapd->own_addr, ETH_ALEN);
434 head->u.beacon.beacon_int =
435 host_to_le16(hapd->iconf->beacon_int);
436
437 /* hardware or low-level driver will setup seq_ctrl and timestamp */
438 capab_info = hostapd_own_capab_info(hapd, NULL, 0);
439 head->u.beacon.capab_info = host_to_le16(capab_info);
440 pos = &head->u.beacon.variable[0];
441
442 /* SSID */
443 *pos++ = WLAN_EID_SSID;
444 if (hapd->conf->ignore_broadcast_ssid == 2) {
445 /* clear the data, but keep the correct length of the SSID */
446 *pos++ = hapd->conf->ssid.ssid_len;
447 os_memset(pos, 0, hapd->conf->ssid.ssid_len);
448 pos += hapd->conf->ssid.ssid_len;
449 } else if (hapd->conf->ignore_broadcast_ssid) {
450 *pos++ = 0; /* empty SSID */
451 } else {
452 *pos++ = hapd->conf->ssid.ssid_len;
453 os_memcpy(pos, hapd->conf->ssid.ssid,
454 hapd->conf->ssid.ssid_len);
455 pos += hapd->conf->ssid.ssid_len;
456 }
457
458 /* Supported rates */
459 pos = hostapd_eid_supp_rates(hapd, pos);
460
461 /* DS Params */
462 pos = hostapd_eid_ds_params(hapd, pos);
463
464 head_len = pos - (u8 *) head;
465
466 tailpos = hostapd_eid_country(hapd, tailpos,
467 tail + BEACON_TAIL_BUF_SIZE - tailpos);
468
469 /* ERP Information element */
470 tailpos = hostapd_eid_erp_info(hapd, tailpos);
471
472 /* Extended supported rates */
473 tailpos = hostapd_eid_ext_supp_rates(hapd, tailpos);
474
475 /* RSN, MDIE, WPA */
476 tailpos = hostapd_eid_wpa(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE -
477 tailpos, NULL);
478
479 #ifdef CONFIG_IEEE80211N
480 tailpos = hostapd_eid_ht_capabilities(hapd, tailpos);
481 tailpos = hostapd_eid_ht_operation(hapd, tailpos);
482 #endif /* CONFIG_IEEE80211N */
483
484 tailpos = hostapd_eid_ext_capab(hapd, tailpos);
485
486 /* Wi-Fi Alliance WMM */
487 tailpos = hostapd_eid_wmm(hapd, tailpos);
488
489 #ifdef CONFIG_WPS
490 if (hapd->conf->wps_state && hapd->wps_beacon_ie) {
491 os_memcpy(tailpos, wpabuf_head(hapd->wps_beacon_ie),
492 wpabuf_len(hapd->wps_beacon_ie));
493 tailpos += wpabuf_len(hapd->wps_beacon_ie);
494 }
495 #endif /* CONFIG_WPS */
496
497 #ifdef CONFIG_P2P
498 if ((hapd->conf->p2p & P2P_ENABLED) && hapd->p2p_beacon_ie) {
499 os_memcpy(tailpos, wpabuf_head(hapd->p2p_beacon_ie),
500 wpabuf_len(hapd->p2p_beacon_ie));
501 tailpos += wpabuf_len(hapd->p2p_beacon_ie);
502 }
503 #endif /* CONFIG_P2P */
504 #ifdef CONFIG_P2P_MANAGER
505 if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) ==
506 P2P_MANAGE)
507 tailpos = hostapd_eid_p2p_manage(hapd, tailpos);
508 #endif /* CONFIG_P2P_MANAGER */
509
510 tail_len = tailpos > tail ? tailpos - tail : 0;
511
512 if (hostapd_drv_set_beacon(hapd, (u8 *) head, head_len,
513 tail, tail_len, hapd->conf->dtim_period,
514 hapd->iconf->beacon_int))
515 wpa_printf(MSG_ERROR, "Failed to set beacon head/tail or DTIM "
516 "period");
517
518 os_free(tail);
519 os_free(head);
520
521 #ifdef CONFIG_P2P
522 no_beacon:
523 #endif /* CONFIG_P2P */
524 hostapd_set_bss_params(hapd, !!(ieee802_11_erp_info(hapd) &
525 ERP_INFO_USE_PROTECTION));
526 }
527
528
ieee802_11_set_beacons(struct hostapd_iface * iface)529 void ieee802_11_set_beacons(struct hostapd_iface *iface)
530 {
531 size_t i;
532 for (i = 0; i < iface->num_bss; i++)
533 ieee802_11_set_beacon(iface->bss[i]);
534 }
535
536 #endif /* CONFIG_NATIVE_WINDOWS */
537