1 /*
2 * Driver interaction with Linux nl80211/cfg80211 - Scanning
3 * Copyright (c) 2002-2014, Jouni Malinen <j@w1.fi>
4 * Copyright (c) 2007, Johannes Berg <johannes@sipsolutions.net>
5 * Copyright (c) 2009-2010, Atheros Communications
6 *
7 * This software may be distributed under the terms of the BSD license.
8 * See README for more details.
9 */
10
11 #include "includes.h"
12 #include <netlink/genl/genl.h>
13
14 #include "utils/common.h"
15 #include "utils/eloop.h"
16 #include "common/ieee802_11_defs.h"
17 #include "driver_nl80211.h"
18
19
get_noise_for_scan_results(struct nl_msg * msg,void * arg)20 static int get_noise_for_scan_results(struct nl_msg *msg, void *arg)
21 {
22 struct nlattr *tb[NL80211_ATTR_MAX + 1];
23 struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
24 struct nlattr *sinfo[NL80211_SURVEY_INFO_MAX + 1];
25 static struct nla_policy survey_policy[NL80211_SURVEY_INFO_MAX + 1] = {
26 [NL80211_SURVEY_INFO_FREQUENCY] = { .type = NLA_U32 },
27 [NL80211_SURVEY_INFO_NOISE] = { .type = NLA_U8 },
28 };
29 struct wpa_scan_results *scan_results = arg;
30 struct wpa_scan_res *scan_res;
31 size_t i;
32
33 nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
34 genlmsg_attrlen(gnlh, 0), NULL);
35
36 if (!tb[NL80211_ATTR_SURVEY_INFO]) {
37 wpa_printf(MSG_DEBUG, "nl80211: Survey data missing");
38 return NL_SKIP;
39 }
40
41 if (nla_parse_nested(sinfo, NL80211_SURVEY_INFO_MAX,
42 tb[NL80211_ATTR_SURVEY_INFO],
43 survey_policy)) {
44 wpa_printf(MSG_DEBUG, "nl80211: Failed to parse nested "
45 "attributes");
46 return NL_SKIP;
47 }
48
49 if (!sinfo[NL80211_SURVEY_INFO_NOISE])
50 return NL_SKIP;
51
52 if (!sinfo[NL80211_SURVEY_INFO_FREQUENCY])
53 return NL_SKIP;
54
55 for (i = 0; i < scan_results->num; ++i) {
56 scan_res = scan_results->res[i];
57 if (!scan_res)
58 continue;
59 if ((int) nla_get_u32(sinfo[NL80211_SURVEY_INFO_FREQUENCY]) !=
60 scan_res->freq)
61 continue;
62 if (!(scan_res->flags & WPA_SCAN_NOISE_INVALID))
63 continue;
64 scan_res->noise = (s8)
65 nla_get_u8(sinfo[NL80211_SURVEY_INFO_NOISE]);
66 scan_res->flags &= ~WPA_SCAN_NOISE_INVALID;
67 }
68
69 return NL_SKIP;
70 }
71
72
nl80211_get_noise_for_scan_results(struct wpa_driver_nl80211_data * drv,struct wpa_scan_results * scan_res)73 static int nl80211_get_noise_for_scan_results(
74 struct wpa_driver_nl80211_data *drv,
75 struct wpa_scan_results *scan_res)
76 {
77 struct nl_msg *msg;
78
79 msg = nl80211_drv_msg(drv, NLM_F_DUMP, NL80211_CMD_GET_SURVEY);
80 return send_and_recv_msgs(drv, msg, get_noise_for_scan_results,
81 scan_res);
82 }
83
84
85 /**
86 * wpa_driver_nl80211_scan_timeout - Scan timeout to report scan completion
87 * @eloop_ctx: Driver private data
88 * @timeout_ctx: ctx argument given to wpa_driver_nl80211_init()
89 *
90 * This function can be used as registered timeout when starting a scan to
91 * generate a scan completed event if the driver does not report this.
92 */
wpa_driver_nl80211_scan_timeout(void * eloop_ctx,void * timeout_ctx)93 void wpa_driver_nl80211_scan_timeout(void *eloop_ctx, void *timeout_ctx)
94 {
95 struct wpa_driver_nl80211_data *drv = eloop_ctx;
96 if (drv->ap_scan_as_station != NL80211_IFTYPE_UNSPECIFIED) {
97 wpa_driver_nl80211_set_mode(drv->first_bss,
98 drv->ap_scan_as_station);
99 drv->ap_scan_as_station = NL80211_IFTYPE_UNSPECIFIED;
100 }
101 wpa_printf(MSG_DEBUG, "Scan timeout - try to get results");
102 wpa_supplicant_event(timeout_ctx, EVENT_SCAN_RESULTS, NULL);
103 }
104
105
106 static struct nl_msg *
nl80211_scan_common(struct i802_bss * bss,u8 cmd,struct wpa_driver_scan_params * params)107 nl80211_scan_common(struct i802_bss *bss, u8 cmd,
108 struct wpa_driver_scan_params *params)
109 {
110 struct wpa_driver_nl80211_data *drv = bss->drv;
111 struct nl_msg *msg;
112 size_t i;
113 u32 scan_flags = 0;
114
115 msg = nl80211_cmd_msg(bss, 0, cmd);
116 if (!msg)
117 return NULL;
118
119 if (params->num_ssids) {
120 struct nlattr *ssids;
121
122 ssids = nla_nest_start(msg, NL80211_ATTR_SCAN_SSIDS);
123 if (ssids == NULL)
124 goto fail;
125 for (i = 0; i < params->num_ssids; i++) {
126 wpa_hexdump_ascii(MSG_MSGDUMP, "nl80211: Scan SSID",
127 params->ssids[i].ssid,
128 params->ssids[i].ssid_len);
129 if (nla_put(msg, i + 1, params->ssids[i].ssid_len,
130 params->ssids[i].ssid))
131 goto fail;
132 }
133 nla_nest_end(msg, ssids);
134 }
135
136 if (params->extra_ies) {
137 wpa_hexdump(MSG_MSGDUMP, "nl80211: Scan extra IEs",
138 params->extra_ies, params->extra_ies_len);
139 if (nla_put(msg, NL80211_ATTR_IE, params->extra_ies_len,
140 params->extra_ies))
141 goto fail;
142 }
143
144 if (params->freqs) {
145 struct nlattr *freqs;
146 freqs = nla_nest_start(msg, NL80211_ATTR_SCAN_FREQUENCIES);
147 if (freqs == NULL)
148 goto fail;
149 for (i = 0; params->freqs[i]; i++) {
150 wpa_printf(MSG_MSGDUMP, "nl80211: Scan frequency %u "
151 "MHz", params->freqs[i]);
152 if (nla_put_u32(msg, i + 1, params->freqs[i]))
153 goto fail;
154 }
155 nla_nest_end(msg, freqs);
156 }
157
158 os_free(drv->filter_ssids);
159 drv->filter_ssids = params->filter_ssids;
160 params->filter_ssids = NULL;
161 drv->num_filter_ssids = params->num_filter_ssids;
162
163 if (params->only_new_results) {
164 wpa_printf(MSG_DEBUG, "nl80211: Add NL80211_SCAN_FLAG_FLUSH");
165 scan_flags |= NL80211_SCAN_FLAG_FLUSH;
166 }
167
168 if (params->low_priority && drv->have_low_prio_scan) {
169 wpa_printf(MSG_DEBUG,
170 "nl80211: Add NL80211_SCAN_FLAG_LOW_PRIORITY");
171 scan_flags |= NL80211_SCAN_FLAG_LOW_PRIORITY;
172 }
173
174 if (params->mac_addr_rand) {
175 wpa_printf(MSG_DEBUG,
176 "nl80211: Add NL80211_SCAN_FLAG_RANDOM_ADDR");
177 scan_flags |= NL80211_SCAN_FLAG_RANDOM_ADDR;
178
179 if (params->mac_addr) {
180 wpa_printf(MSG_DEBUG, "nl80211: MAC address: " MACSTR,
181 MAC2STR(params->mac_addr));
182 if (nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN,
183 params->mac_addr))
184 goto fail;
185 }
186
187 if (params->mac_addr_mask) {
188 wpa_printf(MSG_DEBUG, "nl80211: MAC address mask: "
189 MACSTR, MAC2STR(params->mac_addr_mask));
190 if (nla_put(msg, NL80211_ATTR_MAC_MASK, ETH_ALEN,
191 params->mac_addr_mask))
192 goto fail;
193 }
194 }
195
196 if (scan_flags &&
197 nla_put_u32(msg, NL80211_ATTR_SCAN_FLAGS, scan_flags))
198 goto fail;
199
200 return msg;
201
202 fail:
203 nlmsg_free(msg);
204 return NULL;
205 }
206
207
208 /**
209 * wpa_driver_nl80211_scan - Request the driver to initiate scan
210 * @bss: Pointer to private driver data from wpa_driver_nl80211_init()
211 * @params: Scan parameters
212 * Returns: 0 on success, -1 on failure
213 */
wpa_driver_nl80211_scan(struct i802_bss * bss,struct wpa_driver_scan_params * params)214 int wpa_driver_nl80211_scan(struct i802_bss *bss,
215 struct wpa_driver_scan_params *params)
216 {
217 struct wpa_driver_nl80211_data *drv = bss->drv;
218 int ret = -1, timeout;
219 struct nl_msg *msg = NULL;
220
221 wpa_dbg(drv->ctx, MSG_DEBUG, "nl80211: scan request");
222 drv->scan_for_auth = 0;
223
224 msg = nl80211_scan_common(bss, NL80211_CMD_TRIGGER_SCAN, params);
225 if (!msg)
226 return -1;
227
228 if (params->p2p_probe) {
229 struct nlattr *rates;
230
231 wpa_printf(MSG_DEBUG, "nl80211: P2P probe - mask SuppRates");
232
233 rates = nla_nest_start(msg, NL80211_ATTR_SCAN_SUPP_RATES);
234 if (rates == NULL)
235 goto fail;
236
237 /*
238 * Remove 2.4 GHz rates 1, 2, 5.5, 11 Mbps from supported rates
239 * by masking out everything else apart from the OFDM rates 6,
240 * 9, 12, 18, 24, 36, 48, 54 Mbps from non-MCS rates. All 5 GHz
241 * rates are left enabled.
242 */
243 if (nla_put(msg, NL80211_BAND_2GHZ, 8,
244 "\x0c\x12\x18\x24\x30\x48\x60\x6c"))
245 goto fail;
246 nla_nest_end(msg, rates);
247
248 if (nla_put_flag(msg, NL80211_ATTR_TX_NO_CCK_RATE))
249 goto fail;
250 }
251
252 ret = send_and_recv_msgs(drv, msg, NULL, NULL);
253 msg = NULL;
254 if (ret) {
255 wpa_printf(MSG_DEBUG, "nl80211: Scan trigger failed: ret=%d "
256 "(%s)", ret, strerror(-ret));
257 if (drv->hostapd && is_ap_interface(drv->nlmode)) {
258 enum nl80211_iftype old_mode = drv->nlmode;
259
260 /*
261 * mac80211 does not allow scan requests in AP mode, so
262 * try to do this in station mode.
263 */
264 if (wpa_driver_nl80211_set_mode(
265 bss, NL80211_IFTYPE_STATION))
266 goto fail;
267
268 if (wpa_driver_nl80211_scan(bss, params)) {
269 wpa_driver_nl80211_set_mode(bss, old_mode);
270 goto fail;
271 }
272
273 /* Restore AP mode when processing scan results */
274 drv->ap_scan_as_station = old_mode;
275 ret = 0;
276 } else
277 goto fail;
278 }
279
280 drv->scan_state = SCAN_REQUESTED;
281 /* Not all drivers generate "scan completed" wireless event, so try to
282 * read results after a timeout. */
283 timeout = 10;
284 if (drv->scan_complete_events) {
285 /*
286 * The driver seems to deliver events to notify when scan is
287 * complete, so use longer timeout to avoid race conditions
288 * with scanning and following association request.
289 */
290 timeout = 30;
291 }
292 wpa_printf(MSG_DEBUG, "Scan requested (ret=%d) - scan timeout %d "
293 "seconds", ret, timeout);
294 eloop_cancel_timeout(wpa_driver_nl80211_scan_timeout, drv, drv->ctx);
295 eloop_register_timeout(timeout, 0, wpa_driver_nl80211_scan_timeout,
296 drv, drv->ctx);
297
298 fail:
299 nlmsg_free(msg);
300 return ret;
301 }
302
303
304 /**
305 * wpa_driver_nl80211_sched_scan - Initiate a scheduled scan
306 * @priv: Pointer to private driver data from wpa_driver_nl80211_init()
307 * @params: Scan parameters
308 * @interval: Interval between scan cycles in milliseconds
309 * Returns: 0 on success, -1 on failure or if not supported
310 */
wpa_driver_nl80211_sched_scan(void * priv,struct wpa_driver_scan_params * params,u32 interval)311 int wpa_driver_nl80211_sched_scan(void *priv,
312 struct wpa_driver_scan_params *params,
313 u32 interval)
314 {
315 struct i802_bss *bss = priv;
316 struct wpa_driver_nl80211_data *drv = bss->drv;
317 int ret = -1;
318 struct nl_msg *msg;
319 size_t i;
320
321 wpa_dbg(drv->ctx, MSG_DEBUG, "nl80211: sched_scan request");
322
323 #ifdef ANDROID
324 if (!drv->capa.sched_scan_supported)
325 return android_pno_start(bss, params);
326 #endif /* ANDROID */
327
328 msg = nl80211_scan_common(bss, NL80211_CMD_START_SCHED_SCAN, params);
329 if (!msg ||
330 nla_put_u32(msg, NL80211_ATTR_SCHED_SCAN_INTERVAL, interval))
331 goto fail;
332
333 if ((drv->num_filter_ssids &&
334 (int) drv->num_filter_ssids <= drv->capa.max_match_sets) ||
335 params->filter_rssi) {
336 struct nlattr *match_sets;
337 match_sets = nla_nest_start(msg, NL80211_ATTR_SCHED_SCAN_MATCH);
338 if (match_sets == NULL)
339 goto fail;
340
341 for (i = 0; i < drv->num_filter_ssids; i++) {
342 struct nlattr *match_set_ssid;
343 wpa_hexdump_ascii(MSG_MSGDUMP,
344 "nl80211: Sched scan filter SSID",
345 drv->filter_ssids[i].ssid,
346 drv->filter_ssids[i].ssid_len);
347
348 match_set_ssid = nla_nest_start(msg, i + 1);
349 if (match_set_ssid == NULL ||
350 nla_put(msg, NL80211_ATTR_SCHED_SCAN_MATCH_SSID,
351 drv->filter_ssids[i].ssid_len,
352 drv->filter_ssids[i].ssid) ||
353 (params->filter_rssi &&
354 nla_put_u32(msg,
355 NL80211_SCHED_SCAN_MATCH_ATTR_RSSI,
356 params->filter_rssi)))
357 goto fail;
358
359 nla_nest_end(msg, match_set_ssid);
360 }
361
362 /*
363 * Due to backward compatibility code, newer kernels treat this
364 * matchset (with only an RSSI filter) as the default for all
365 * other matchsets, unless it's the only one, in which case the
366 * matchset will actually allow all SSIDs above the RSSI.
367 */
368 if (params->filter_rssi) {
369 struct nlattr *match_set_rssi;
370 match_set_rssi = nla_nest_start(msg, 0);
371 if (match_set_rssi == NULL ||
372 nla_put_u32(msg, NL80211_SCHED_SCAN_MATCH_ATTR_RSSI,
373 params->filter_rssi))
374 goto fail;
375 wpa_printf(MSG_MSGDUMP,
376 "nl80211: Sched scan RSSI filter %d dBm",
377 params->filter_rssi);
378 nla_nest_end(msg, match_set_rssi);
379 }
380
381 nla_nest_end(msg, match_sets);
382 }
383
384 ret = send_and_recv_msgs(drv, msg, NULL, NULL);
385
386 /* TODO: if we get an error here, we should fall back to normal scan */
387
388 msg = NULL;
389 if (ret) {
390 wpa_printf(MSG_DEBUG, "nl80211: Sched scan start failed: "
391 "ret=%d (%s)", ret, strerror(-ret));
392 goto fail;
393 }
394
395 wpa_printf(MSG_DEBUG, "nl80211: Sched scan requested (ret=%d) - "
396 "scan interval %d msec", ret, interval);
397
398 fail:
399 nlmsg_free(msg);
400 return ret;
401 }
402
403
404 /**
405 * wpa_driver_nl80211_stop_sched_scan - Stop a scheduled scan
406 * @priv: Pointer to private driver data from wpa_driver_nl80211_init()
407 * Returns: 0 on success, -1 on failure or if not supported
408 */
wpa_driver_nl80211_stop_sched_scan(void * priv)409 int wpa_driver_nl80211_stop_sched_scan(void *priv)
410 {
411 struct i802_bss *bss = priv;
412 struct wpa_driver_nl80211_data *drv = bss->drv;
413 int ret;
414 struct nl_msg *msg;
415
416 #ifdef ANDROID
417 if (!drv->capa.sched_scan_supported)
418 return android_pno_stop(bss);
419 #endif /* ANDROID */
420
421 msg = nl80211_drv_msg(drv, 0, NL80211_CMD_STOP_SCHED_SCAN);
422 ret = send_and_recv_msgs(drv, msg, NULL, NULL);
423 if (ret) {
424 wpa_printf(MSG_DEBUG,
425 "nl80211: Sched scan stop failed: ret=%d (%s)",
426 ret, strerror(-ret));
427 } else {
428 wpa_printf(MSG_DEBUG,
429 "nl80211: Sched scan stop sent");
430 }
431
432 return ret;
433 }
434
435
nl80211_get_ie(const u8 * ies,size_t ies_len,u8 ie)436 const u8 * nl80211_get_ie(const u8 *ies, size_t ies_len, u8 ie)
437 {
438 const u8 *end, *pos;
439
440 if (ies == NULL)
441 return NULL;
442
443 pos = ies;
444 end = ies + ies_len;
445
446 while (pos + 1 < end) {
447 if (pos + 2 + pos[1] > end)
448 break;
449 if (pos[0] == ie)
450 return pos;
451 pos += 2 + pos[1];
452 }
453
454 return NULL;
455 }
456
457
nl80211_scan_filtered(struct wpa_driver_nl80211_data * drv,const u8 * ie,size_t ie_len)458 static int nl80211_scan_filtered(struct wpa_driver_nl80211_data *drv,
459 const u8 *ie, size_t ie_len)
460 {
461 const u8 *ssid;
462 size_t i;
463
464 if (drv->filter_ssids == NULL)
465 return 0;
466
467 ssid = nl80211_get_ie(ie, ie_len, WLAN_EID_SSID);
468 if (ssid == NULL)
469 return 1;
470
471 for (i = 0; i < drv->num_filter_ssids; i++) {
472 if (ssid[1] == drv->filter_ssids[i].ssid_len &&
473 os_memcmp(ssid + 2, drv->filter_ssids[i].ssid, ssid[1]) ==
474 0)
475 return 0;
476 }
477
478 return 1;
479 }
480
481
bss_info_handler(struct nl_msg * msg,void * arg)482 int bss_info_handler(struct nl_msg *msg, void *arg)
483 {
484 struct nlattr *tb[NL80211_ATTR_MAX + 1];
485 struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
486 struct nlattr *bss[NL80211_BSS_MAX + 1];
487 static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
488 [NL80211_BSS_BSSID] = { .type = NLA_UNSPEC },
489 [NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
490 [NL80211_BSS_TSF] = { .type = NLA_U64 },
491 [NL80211_BSS_BEACON_INTERVAL] = { .type = NLA_U16 },
492 [NL80211_BSS_CAPABILITY] = { .type = NLA_U16 },
493 [NL80211_BSS_INFORMATION_ELEMENTS] = { .type = NLA_UNSPEC },
494 [NL80211_BSS_SIGNAL_MBM] = { .type = NLA_U32 },
495 [NL80211_BSS_SIGNAL_UNSPEC] = { .type = NLA_U8 },
496 [NL80211_BSS_STATUS] = { .type = NLA_U32 },
497 [NL80211_BSS_SEEN_MS_AGO] = { .type = NLA_U32 },
498 [NL80211_BSS_BEACON_IES] = { .type = NLA_UNSPEC },
499 };
500 struct nl80211_bss_info_arg *_arg = arg;
501 struct wpa_scan_results *res = _arg->res;
502 struct wpa_scan_res **tmp;
503 struct wpa_scan_res *r;
504 const u8 *ie, *beacon_ie;
505 size_t ie_len, beacon_ie_len;
506 u8 *pos;
507 size_t i;
508
509 nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
510 genlmsg_attrlen(gnlh, 0), NULL);
511 if (!tb[NL80211_ATTR_BSS])
512 return NL_SKIP;
513 if (nla_parse_nested(bss, NL80211_BSS_MAX, tb[NL80211_ATTR_BSS],
514 bss_policy))
515 return NL_SKIP;
516 if (bss[NL80211_BSS_STATUS]) {
517 enum nl80211_bss_status status;
518 status = nla_get_u32(bss[NL80211_BSS_STATUS]);
519 if (status == NL80211_BSS_STATUS_ASSOCIATED &&
520 bss[NL80211_BSS_FREQUENCY]) {
521 _arg->assoc_freq =
522 nla_get_u32(bss[NL80211_BSS_FREQUENCY]);
523 wpa_printf(MSG_DEBUG, "nl80211: Associated on %u MHz",
524 _arg->assoc_freq);
525 }
526 if (status == NL80211_BSS_STATUS_IBSS_JOINED &&
527 bss[NL80211_BSS_FREQUENCY]) {
528 _arg->ibss_freq =
529 nla_get_u32(bss[NL80211_BSS_FREQUENCY]);
530 wpa_printf(MSG_DEBUG, "nl80211: IBSS-joined on %u MHz",
531 _arg->ibss_freq);
532 }
533 if (status == NL80211_BSS_STATUS_ASSOCIATED &&
534 bss[NL80211_BSS_BSSID]) {
535 os_memcpy(_arg->assoc_bssid,
536 nla_data(bss[NL80211_BSS_BSSID]), ETH_ALEN);
537 wpa_printf(MSG_DEBUG, "nl80211: Associated with "
538 MACSTR, MAC2STR(_arg->assoc_bssid));
539 }
540 }
541 if (!res)
542 return NL_SKIP;
543 if (bss[NL80211_BSS_INFORMATION_ELEMENTS]) {
544 ie = nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
545 ie_len = nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
546 } else {
547 ie = NULL;
548 ie_len = 0;
549 }
550 if (bss[NL80211_BSS_BEACON_IES]) {
551 beacon_ie = nla_data(bss[NL80211_BSS_BEACON_IES]);
552 beacon_ie_len = nla_len(bss[NL80211_BSS_BEACON_IES]);
553 } else {
554 beacon_ie = NULL;
555 beacon_ie_len = 0;
556 }
557
558 if (nl80211_scan_filtered(_arg->drv, ie ? ie : beacon_ie,
559 ie ? ie_len : beacon_ie_len))
560 return NL_SKIP;
561
562 r = os_zalloc(sizeof(*r) + ie_len + beacon_ie_len);
563 if (r == NULL)
564 return NL_SKIP;
565 if (bss[NL80211_BSS_BSSID])
566 os_memcpy(r->bssid, nla_data(bss[NL80211_BSS_BSSID]),
567 ETH_ALEN);
568 if (bss[NL80211_BSS_FREQUENCY])
569 r->freq = nla_get_u32(bss[NL80211_BSS_FREQUENCY]);
570 if (bss[NL80211_BSS_BEACON_INTERVAL])
571 r->beacon_int = nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]);
572 if (bss[NL80211_BSS_CAPABILITY])
573 r->caps = nla_get_u16(bss[NL80211_BSS_CAPABILITY]);
574 r->flags |= WPA_SCAN_NOISE_INVALID;
575 if (bss[NL80211_BSS_SIGNAL_MBM]) {
576 r->level = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
577 r->level /= 100; /* mBm to dBm */
578 r->flags |= WPA_SCAN_LEVEL_DBM | WPA_SCAN_QUAL_INVALID;
579 } else if (bss[NL80211_BSS_SIGNAL_UNSPEC]) {
580 r->level = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
581 r->flags |= WPA_SCAN_QUAL_INVALID;
582 } else
583 r->flags |= WPA_SCAN_LEVEL_INVALID | WPA_SCAN_QUAL_INVALID;
584 if (bss[NL80211_BSS_TSF])
585 r->tsf = nla_get_u64(bss[NL80211_BSS_TSF]);
586 if (bss[NL80211_BSS_SEEN_MS_AGO])
587 r->age = nla_get_u32(bss[NL80211_BSS_SEEN_MS_AGO]);
588 r->ie_len = ie_len;
589 pos = (u8 *) (r + 1);
590 if (ie) {
591 os_memcpy(pos, ie, ie_len);
592 pos += ie_len;
593 }
594 r->beacon_ie_len = beacon_ie_len;
595 if (beacon_ie)
596 os_memcpy(pos, beacon_ie, beacon_ie_len);
597
598 if (bss[NL80211_BSS_STATUS]) {
599 enum nl80211_bss_status status;
600 status = nla_get_u32(bss[NL80211_BSS_STATUS]);
601 switch (status) {
602 case NL80211_BSS_STATUS_ASSOCIATED:
603 r->flags |= WPA_SCAN_ASSOCIATED;
604 break;
605 default:
606 break;
607 }
608 }
609
610 /*
611 * cfg80211 maintains separate BSS table entries for APs if the same
612 * BSSID,SSID pair is seen on multiple channels. wpa_supplicant does
613 * not use frequency as a separate key in the BSS table, so filter out
614 * duplicated entries. Prefer associated BSS entry in such a case in
615 * order to get the correct frequency into the BSS table. Similarly,
616 * prefer newer entries over older.
617 */
618 for (i = 0; i < res->num; i++) {
619 const u8 *s1, *s2;
620 if (os_memcmp(res->res[i]->bssid, r->bssid, ETH_ALEN) != 0)
621 continue;
622
623 s1 = nl80211_get_ie((u8 *) (res->res[i] + 1),
624 res->res[i]->ie_len, WLAN_EID_SSID);
625 s2 = nl80211_get_ie((u8 *) (r + 1), r->ie_len, WLAN_EID_SSID);
626 if (s1 == NULL || s2 == NULL || s1[1] != s2[1] ||
627 os_memcmp(s1, s2, 2 + s1[1]) != 0)
628 continue;
629
630 /* Same BSSID,SSID was already included in scan results */
631 wpa_printf(MSG_DEBUG, "nl80211: Remove duplicated scan result "
632 "for " MACSTR, MAC2STR(r->bssid));
633
634 if (((r->flags & WPA_SCAN_ASSOCIATED) &&
635 !(res->res[i]->flags & WPA_SCAN_ASSOCIATED)) ||
636 r->age < res->res[i]->age) {
637 os_free(res->res[i]);
638 res->res[i] = r;
639 } else
640 os_free(r);
641 return NL_SKIP;
642 }
643
644 tmp = os_realloc_array(res->res, res->num + 1,
645 sizeof(struct wpa_scan_res *));
646 if (tmp == NULL) {
647 os_free(r);
648 return NL_SKIP;
649 }
650 tmp[res->num++] = r;
651 res->res = tmp;
652
653 return NL_SKIP;
654 }
655
656
clear_state_mismatch(struct wpa_driver_nl80211_data * drv,const u8 * addr)657 static void clear_state_mismatch(struct wpa_driver_nl80211_data *drv,
658 const u8 *addr)
659 {
660 if (drv->capa.flags & WPA_DRIVER_FLAGS_SME) {
661 wpa_printf(MSG_DEBUG, "nl80211: Clear possible state "
662 "mismatch (" MACSTR ")", MAC2STR(addr));
663 wpa_driver_nl80211_mlme(drv, addr,
664 NL80211_CMD_DEAUTHENTICATE,
665 WLAN_REASON_PREV_AUTH_NOT_VALID, 1);
666 }
667 }
668
669
wpa_driver_nl80211_check_bss_status(struct wpa_driver_nl80211_data * drv,struct wpa_scan_results * res)670 static void wpa_driver_nl80211_check_bss_status(
671 struct wpa_driver_nl80211_data *drv, struct wpa_scan_results *res)
672 {
673 size_t i;
674
675 for (i = 0; i < res->num; i++) {
676 struct wpa_scan_res *r = res->res[i];
677
678 if (r->flags & WPA_SCAN_ASSOCIATED) {
679 wpa_printf(MSG_DEBUG, "nl80211: Scan results "
680 "indicate BSS status with " MACSTR
681 " as associated",
682 MAC2STR(r->bssid));
683 if (is_sta_interface(drv->nlmode) &&
684 !drv->associated) {
685 wpa_printf(MSG_DEBUG, "nl80211: Local state "
686 "(not associated) does not match "
687 "with BSS state");
688 clear_state_mismatch(drv, r->bssid);
689 } else if (is_sta_interface(drv->nlmode) &&
690 os_memcmp(drv->bssid, r->bssid, ETH_ALEN) !=
691 0) {
692 wpa_printf(MSG_DEBUG, "nl80211: Local state "
693 "(associated with " MACSTR ") does "
694 "not match with BSS state",
695 MAC2STR(drv->bssid));
696 clear_state_mismatch(drv, r->bssid);
697 clear_state_mismatch(drv, drv->bssid);
698 }
699 }
700 }
701 }
702
703
704 static struct wpa_scan_results *
nl80211_get_scan_results(struct wpa_driver_nl80211_data * drv)705 nl80211_get_scan_results(struct wpa_driver_nl80211_data *drv)
706 {
707 struct nl_msg *msg;
708 struct wpa_scan_results *res;
709 int ret;
710 struct nl80211_bss_info_arg arg;
711
712 res = os_zalloc(sizeof(*res));
713 if (res == NULL)
714 return NULL;
715 if (!(msg = nl80211_cmd_msg(drv->first_bss, NLM_F_DUMP,
716 NL80211_CMD_GET_SCAN))) {
717 wpa_scan_results_free(res);
718 return NULL;
719 }
720
721 arg.drv = drv;
722 arg.res = res;
723 ret = send_and_recv_msgs(drv, msg, bss_info_handler, &arg);
724 if (ret == 0) {
725 wpa_printf(MSG_DEBUG, "nl80211: Received scan results (%lu "
726 "BSSes)", (unsigned long) res->num);
727 nl80211_get_noise_for_scan_results(drv, res);
728 return res;
729 }
730 wpa_printf(MSG_DEBUG, "nl80211: Scan result fetch failed: ret=%d "
731 "(%s)", ret, strerror(-ret));
732 wpa_scan_results_free(res);
733 return NULL;
734 }
735
736
737 /**
738 * wpa_driver_nl80211_get_scan_results - Fetch the latest scan results
739 * @priv: Pointer to private wext data from wpa_driver_nl80211_init()
740 * Returns: Scan results on success, -1 on failure
741 */
wpa_driver_nl80211_get_scan_results(void * priv)742 struct wpa_scan_results * wpa_driver_nl80211_get_scan_results(void *priv)
743 {
744 struct i802_bss *bss = priv;
745 struct wpa_driver_nl80211_data *drv = bss->drv;
746 struct wpa_scan_results *res;
747
748 res = nl80211_get_scan_results(drv);
749 if (res)
750 wpa_driver_nl80211_check_bss_status(drv, res);
751 return res;
752 }
753
754
nl80211_dump_scan(struct wpa_driver_nl80211_data * drv)755 void nl80211_dump_scan(struct wpa_driver_nl80211_data *drv)
756 {
757 struct wpa_scan_results *res;
758 size_t i;
759
760 res = nl80211_get_scan_results(drv);
761 if (res == NULL) {
762 wpa_printf(MSG_DEBUG, "nl80211: Failed to get scan results");
763 return;
764 }
765
766 wpa_printf(MSG_DEBUG, "nl80211: Scan result dump");
767 for (i = 0; i < res->num; i++) {
768 struct wpa_scan_res *r = res->res[i];
769 wpa_printf(MSG_DEBUG, "nl80211: %d/%d " MACSTR "%s",
770 (int) i, (int) res->num, MAC2STR(r->bssid),
771 r->flags & WPA_SCAN_ASSOCIATED ? " [assoc]" : "");
772 }
773
774 wpa_scan_results_free(res);
775 }
776