contrib/wpa/src/drivers/driver_nl80211_scan.c

   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
  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
  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  */
  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 *
 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  */
 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  */
 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  */
 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
 436 static 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
 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
 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
 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
 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 *
 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  */
 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
 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 }