net/wireless/scan.c

   1 /*
   2  * cfg80211 scan result handling
   3  *
   4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
   5  */
   6 #include <linux/kernel.h>
   7 #include <linux/module.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/wireless.h>
  10 #include <linux/nl80211.h>
  11 #include <linux/etherdevice.h>
  12 #include <net/arp.h>
  13 #include <net/cfg80211.h>
  14 #include <net/iw_handler.h>
  15 #include "core.h"
  16 #include "nl80211.h"
  17
  18 #define IEEE80211_SCAN_RESULT_EXPIRE    (10 * HZ)
  19
  20 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  21 {
  22         struct net_device *dev;
  23 #ifdef CONFIG_WIRELESS_EXT
  24         union iwreq_data wrqu;
  25 #endif
  26
  27         dev = dev_get_by_index(&init_net, request->ifidx);
  28         if (!dev)
  29                 goto out;
  30
  31         /*
  32          * This must be before sending the other events!
  33          * Otherwise, wpa_supplicant gets completely confused with
  34          * wext events.
  35          */
  36         cfg80211_sme_scan_done(dev);
  37
  38         if (aborted)
  39                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  40         else
  41                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  42
  43         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  44
  45 #ifdef CONFIG_WIRELESS_EXT
  46         if (!aborted) {
  47                 memset(&wrqu, 0, sizeof(wrqu));
  48
  49                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  50         }
  51 #endif
  52
  53         dev_put(dev);
  54
  55  out:
  56         kfree(request);
  57 }
  58 EXPORT_SYMBOL(cfg80211_scan_done);
  59
  60 static void bss_release(struct kref *ref)
  61 {
  62         struct cfg80211_internal_bss *bss;
  63
  64         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  65         if (bss->pub.free_priv)
  66                 bss->pub.free_priv(&bss->pub);
  67
  68         if (bss->ies_allocated)
  69                 kfree(bss->pub.information_elements);
  70
  71         BUG_ON(atomic_read(&bss->hold));
  72
  73         kfree(bss);
  74 }
  75
  76 /* must hold dev->bss_lock! */
  77 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
  78                       unsigned long age_secs)
  79 {
  80         struct cfg80211_internal_bss *bss;
  81         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
  82
  83         list_for_each_entry(bss, &dev->bss_list, list) {
  84                 bss->ts -= age_jiffies;
  85         }
  86 }
  87
  88 /* must hold dev->bss_lock! */
  89 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
  90 {
  91         struct cfg80211_internal_bss *bss, *tmp;
  92         bool expired = false;
  93
  94         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
  95                 if (atomic_read(&bss->hold))
  96                         continue;
  97                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
  98                         continue;
  99                 list_del(&bss->list);
 100                 rb_erase(&bss->rbn, &dev->bss_tree);
 101                 kref_put(&bss->ref, bss_release);
 102                 expired = true;
 103         }
 104
 105         if (expired)
 106                 dev->bss_generation++;
 107 }
 108
 109 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 110 {
 111         while (len > 2 && ies[0] != num) {
 112                 len -= ies[1] + 2;
 113                 ies += ies[1] + 2;
 114         }
 115         if (len < 2)
 116                 return NULL;
 117         if (len < 2 + ies[1])
 118                 return NULL;
 119         return ies;
 120 }
 121
 122 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 123 {
 124         const u8 *ie1 = find_ie(num, ies1, len1);
 125         const u8 *ie2 = find_ie(num, ies2, len2);
 126         int r;
 127
 128         if (!ie1 && !ie2)
 129                 return 0;
 130         if (!ie1)
 131                 return -1;
 132
 133         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 134         if (r == 0 && ie1[1] != ie2[1])
 135                 return ie2[1] - ie1[1];
 136         return r;
 137 }
 138
 139 static bool is_bss(struct cfg80211_bss *a,
 140                    const u8 *bssid,
 141                    const u8 *ssid, size_t ssid_len)
 142 {
 143         const u8 *ssidie;
 144
 145         if (bssid && compare_ether_addr(a->bssid, bssid))
 146                 return false;
 147
 148         if (!ssid)
 149                 return true;
 150
 151         ssidie = find_ie(WLAN_EID_SSID,
 152                          a->information_elements,
 153                          a->len_information_elements);
 154         if (!ssidie)
 155                 return false;
 156         if (ssidie[1] != ssid_len)
 157                 return false;
 158         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 159 }
 160
 161 static bool is_mesh(struct cfg80211_bss *a,
 162                     const u8 *meshid, size_t meshidlen,
 163                     const u8 *meshcfg)
 164 {
 165         const u8 *ie;
 166
 167         if (!is_zero_ether_addr(a->bssid))
 168                 return false;
 169
 170         ie = find_ie(WLAN_EID_MESH_ID,
 171                      a->information_elements,
 172                      a->len_information_elements);
 173         if (!ie)
 174                 return false;
 175         if (ie[1] != meshidlen)
 176                 return false;
 177         if (memcmp(ie + 2, meshid, meshidlen))
 178                 return false;
 179
 180         ie = find_ie(WLAN_EID_MESH_CONFIG,
 181                      a->information_elements,
 182                      a->len_information_elements);
 183         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 184                 return false;
 185
 186         /*
 187          * Ignore mesh capability (last two bytes of the IE) when
 188          * comparing since that may differ between stations taking
 189          * part in the same mesh.
 190          */
 191         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 192 }
 193
 194 static int cmp_bss(struct cfg80211_bss *a,
 195                    struct cfg80211_bss *b)
 196 {
 197         int r;
 198
 199         if (a->channel != b->channel)
 200                 return b->channel->center_freq - a->channel->center_freq;
 201
 202         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 203         if (r)
 204                 return r;
 205
 206         if (is_zero_ether_addr(a->bssid)) {
 207                 r = cmp_ies(WLAN_EID_MESH_ID,
 208                             a->information_elements,
 209                             a->len_information_elements,
 210                             b->information_elements,
 211                             b->len_information_elements);
 212                 if (r)
 213                         return r;
 214                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 215                                a->information_elements,
 216                                a->len_information_elements,
 217                                b->information_elements,
 218                                b->len_information_elements);
 219         }
 220
 221         return cmp_ies(WLAN_EID_SSID,
 222                        a->information_elements,
 223                        a->len_information_elements,
 224                        b->information_elements,
 225                        b->len_information_elements);
 226 }
 227
 228 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 229                                       struct ieee80211_channel *channel,
 230                                       const u8 *bssid,
 231                                       const u8 *ssid, size_t ssid_len,
 232                                       u16 capa_mask, u16 capa_val)
 233 {
 234         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 235         struct cfg80211_internal_bss *bss, *res = NULL;
 236
 237         spin_lock_bh(&dev->bss_lock);
 238
 239         list_for_each_entry(bss, &dev->bss_list, list) {
 240                 if ((bss->pub.capability & capa_mask) != capa_val)
 241                         continue;
 242                 if (channel && bss->pub.channel != channel)
 243                         continue;
 244                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 245                         res = bss;
 246                         kref_get(&res->ref);
 247                         break;
 248                 }
 249         }
 250
 251         spin_unlock_bh(&dev->bss_lock);
 252         if (!res)
 253                 return NULL;
 254         return &res->pub;
 255 }
 256 EXPORT_SYMBOL(cfg80211_get_bss);
 257
 258 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 259                                        struct ieee80211_channel *channel,
 260                                        const u8 *meshid, size_t meshidlen,
 261                                        const u8 *meshcfg)
 262 {
 263         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 264         struct cfg80211_internal_bss *bss, *res = NULL;
 265
 266         spin_lock_bh(&dev->bss_lock);
 267
 268         list_for_each_entry(bss, &dev->bss_list, list) {
 269                 if (channel && bss->pub.channel != channel)
 270                         continue;
 271                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 272                         res = bss;
 273                         kref_get(&res->ref);
 274                         break;
 275                 }
 276         }
 277
 278         spin_unlock_bh(&dev->bss_lock);
 279         if (!res)
 280                 return NULL;
 281         return &res->pub;
 282 }
 283 EXPORT_SYMBOL(cfg80211_get_mesh);
 284
 285
 286 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 287                           struct cfg80211_internal_bss *bss)
 288 {
 289         struct rb_node **p = &dev->bss_tree.rb_node;
 290         struct rb_node *parent = NULL;
 291         struct cfg80211_internal_bss *tbss;
 292         int cmp;
 293
 294         while (*p) {
 295                 parent = *p;
 296                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 297
 298                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 299
 300                 if (WARN_ON(!cmp)) {
 301                         /* will sort of leak this BSS */
 302                         return;
 303                 }
 304
 305                 if (cmp < 0)
 306                         p = &(*p)->rb_left;
 307                 else
 308                         p = &(*p)->rb_right;
 309         }
 310
 311         rb_link_node(&bss->rbn, parent, p);
 312         rb_insert_color(&bss->rbn, &dev->bss_tree);
 313 }
 314
 315 static struct cfg80211_internal_bss *
 316 rb_find_bss(struct cfg80211_registered_device *dev,
 317             struct cfg80211_internal_bss *res)
 318 {
 319         struct rb_node *n = dev->bss_tree.rb_node;
 320         struct cfg80211_internal_bss *bss;
 321         int r;
 322
 323         while (n) {
 324                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 325                 r = cmp_bss(&res->pub, &bss->pub);
 326
 327                 if (r == 0)
 328                         return bss;
 329                 else if (r < 0)
 330                         n = n->rb_left;
 331                 else
 332                         n = n->rb_right;
 333         }
 334
 335         return NULL;
 336 }
 337
 338 static struct cfg80211_internal_bss *
 339 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 340                     struct cfg80211_internal_bss *res,
 341                     bool overwrite)
 342 {
 343         struct cfg80211_internal_bss *found = NULL;
 344         const u8 *meshid, *meshcfg;
 345
 346         /*
 347          * The reference to "res" is donated to this function.
 348          */
 349
 350         if (WARN_ON(!res->pub.channel)) {
 351                 kref_put(&res->ref, bss_release);
 352                 return NULL;
 353         }
 354
 355         res->ts = jiffies;
 356
 357         if (is_zero_ether_addr(res->pub.bssid)) {
 358                 /* must be mesh, verify */
 359                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 360                                  res->pub.len_information_elements);
 361                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 362                                   res->pub.information_elements,
 363                                   res->pub.len_information_elements);
 364                 if (!meshid || !meshcfg ||
 365                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 366                         /* bogus mesh */
 367                         kref_put(&res->ref, bss_release);
 368                         return NULL;
 369                 }
 370         }
 371
 372         spin_lock_bh(&dev->bss_lock);
 373
 374         found = rb_find_bss(dev, res);
 375
 376         if (found) {
 377                 found->pub.beacon_interval = res->pub.beacon_interval;
 378                 found->pub.tsf = res->pub.tsf;
 379                 found->pub.signal = res->pub.signal;
 380                 found->pub.capability = res->pub.capability;
 381                 found->ts = res->ts;
 382
 383                 /* overwrite IEs */
 384                 if (overwrite) {
 385                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 386                         size_t ielen = res->pub.len_information_elements;
 387
 388                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 389                                 memcpy(found->pub.information_elements,
 390                                        res->pub.information_elements, ielen);
 391                                 found->pub.len_information_elements = ielen;
 392                         } else {
 393                                 u8 *ies = found->pub.information_elements;
 394
 395                                 if (found->ies_allocated)
 396                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 397                                 else
 398                                         ies = kmalloc(ielen, GFP_ATOMIC);
 399
 400                                 if (ies) {
 401                                         memcpy(ies, res->pub.information_elements, ielen);
 402                                         found->ies_allocated = true;
 403                                         found->pub.information_elements = ies;
 404                                         found->pub.len_information_elements = ielen;
 405                                 }
 406                         }
 407                 }
 408
 409                 kref_put(&res->ref, bss_release);
 410         } else {
 411                 /* this "consumes" the reference */
 412                 list_add_tail(&res->list, &dev->bss_list);
 413                 rb_insert_bss(dev, res);
 414                 found = res;
 415         }
 416
 417         dev->bss_generation++;
 418         spin_unlock_bh(&dev->bss_lock);
 419
 420         kref_get(&found->ref);
 421         return found;
 422 }
 423
 424 struct cfg80211_bss*
 425 cfg80211_inform_bss(struct wiphy *wiphy,
 426                     struct ieee80211_channel *channel,
 427                     const u8 *bssid,
 428                     u64 timestamp, u16 capability, u16 beacon_interval,
 429                     const u8 *ie, size_t ielen,
 430                     s32 signal, gfp_t gfp)
 431 {
 432         struct cfg80211_internal_bss *res;
 433         size_t privsz;
 434
 435         if (WARN_ON(!wiphy))
 436                 return NULL;
 437
 438         privsz = wiphy->bss_priv_size;
 439
 440         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 441                         (signal < 0 || signal > 100)))
 442                 return NULL;
 443
 444         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 445         if (!res)
 446                 return NULL;
 447
 448         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 449         res->pub.channel = channel;
 450         res->pub.signal = signal;
 451         res->pub.tsf = timestamp;
 452         res->pub.beacon_interval = beacon_interval;
 453         res->pub.capability = capability;
 454         /* point to after the private area */
 455         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 456         memcpy(res->pub.information_elements, ie, ielen);
 457         res->pub.len_information_elements = ielen;
 458
 459         kref_init(&res->ref);
 460
 461         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 462         if (!res)
 463                 return NULL;
 464
 465         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 466                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 467
 468         /* cfg80211_bss_update gives us a referenced result */
 469         return &res->pub;
 470 }
 471 EXPORT_SYMBOL(cfg80211_inform_bss);
 472
 473 struct cfg80211_bss *
 474 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 475                           struct ieee80211_channel *channel,
 476                           struct ieee80211_mgmt *mgmt, size_t len,
 477                           s32 signal, gfp_t gfp)
 478 {
 479         struct cfg80211_internal_bss *res;
 480         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 481                                       u.probe_resp.variable);
 482         bool overwrite;
 483         size_t privsz = wiphy->bss_priv_size;
 484
 485         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 486                     (signal < 0 || signal > 100)))
 487                 return NULL;
 488
 489         if (WARN_ON(!mgmt || !wiphy ||
 490                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 491                 return NULL;
 492
 493         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 494         if (!res)
 495                 return NULL;
 496
 497         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 498         res->pub.channel = channel;
 499         res->pub.signal = signal;
 500         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 501         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 502         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 503         /* point to after the private area */
 504         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 505         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 506         res->pub.len_information_elements = ielen;
 507
 508         kref_init(&res->ref);
 509
 510         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 511
 512         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 513         if (!res)
 514                 return NULL;
 515
 516         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 517                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 518
 519         /* cfg80211_bss_update gives us a referenced result */
 520         return &res->pub;
 521 }
 522 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 523
 524 void cfg80211_put_bss(struct cfg80211_bss *pub)
 525 {
 526         struct cfg80211_internal_bss *bss;
 527
 528         if (!pub)
 529                 return;
 530
 531         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 532         kref_put(&bss->ref, bss_release);
 533 }
 534 EXPORT_SYMBOL(cfg80211_put_bss);
 535
 536 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 537 {
 538         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 539         struct cfg80211_internal_bss *bss;
 540
 541         if (WARN_ON(!pub))
 542                 return;
 543
 544         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 545
 546         spin_lock_bh(&dev->bss_lock);
 547
 548         list_del(&bss->list);
 549         rb_erase(&bss->rbn, &dev->bss_tree);
 550
 551         spin_unlock_bh(&dev->bss_lock);
 552
 553         kref_put(&bss->ref, bss_release);
 554 }
 555 EXPORT_SYMBOL(cfg80211_unlink_bss);
 556
 557 #ifdef CONFIG_WIRELESS_EXT
 558 int cfg80211_wext_siwscan(struct net_device *dev,
 559                           struct iw_request_info *info,
 560                           union iwreq_data *wrqu, char *extra)
 561 {
 562         struct cfg80211_registered_device *rdev;
 563         struct wiphy *wiphy;
 564         struct iw_scan_req *wreq = NULL;
 565         struct cfg80211_scan_request *creq;
 566         int i, err, n_channels = 0;
 567         enum ieee80211_band band;
 568
 569         if (!netif_running(dev))
 570                 return -ENETDOWN;
 571
 572         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 573
 574         if (IS_ERR(rdev))
 575                 return PTR_ERR(rdev);
 576
 577         if (rdev->scan_req) {
 578                 err = -EBUSY;
 579                 goto out;
 580         }
 581
 582         wiphy = &rdev->wiphy;
 583
 584         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 585                 if (wiphy->bands[band])
 586                         n_channels += wiphy->bands[band]->n_channels;
 587
 588         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 589                        n_channels * sizeof(void *),
 590                        GFP_ATOMIC);
 591         if (!creq) {
 592                 err = -ENOMEM;
 593                 goto out;
 594         }
 595
 596         creq->wiphy = wiphy;
 597         creq->ifidx = dev->ifindex;
 598         creq->ssids = (void *)(creq + 1);
 599         creq->channels = (void *)(creq->ssids + 1);
 600         creq->n_channels = n_channels;
 601         creq->n_ssids = 1;
 602
 603         /* all channels */
 604         i = 0;
 605         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 606                 int j;
 607                 if (!wiphy->bands[band])
 608                         continue;
 609                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 610                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 611                         i++;
 612                 }
 613         }
 614
 615         /* translate scan request */
 616         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 617                 wreq = (struct iw_scan_req *)extra;
 618
 619                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 620                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 621                                 return -EINVAL;
 622                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 623                         creq->ssids[0].ssid_len = wreq->essid_len;
 624                 }
 625                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 626                         creq->n_ssids = 0;
 627         }
 628
 629         rdev->scan_req = creq;
 630         err = rdev->ops->scan(wiphy, dev, creq);
 631         if (err) {
 632                 rdev->scan_req = NULL;
 633                 kfree(creq);
 634         } else
 635                 nl80211_send_scan_start(rdev, dev);
 636  out:
 637         cfg80211_unlock_rdev(rdev);
 638         return err;
 639 }
 640 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 641
 642 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 643                                    struct cfg80211_bss *bss,
 644                                    char **current_ev, char *end_buf)
 645 {
 646         u8 *pos, *end, *next;
 647         struct iw_event iwe;
 648
 649         if (!bss->information_elements ||
 650             !bss->len_information_elements)
 651                 return;
 652
 653         /*
 654          * If needed, fragment the IEs buffer (at IE boundaries) into short
 655          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 656          */
 657         pos = bss->information_elements;
 658         end = pos + bss->len_information_elements;
 659
 660         while (end - pos > IW_GENERIC_IE_MAX) {
 661                 next = pos + 2 + pos[1];
 662                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 663                         next = next + 2 + next[1];
 664
 665                 memset(&iwe, 0, sizeof(iwe));
 666                 iwe.cmd = IWEVGENIE;
 667                 iwe.u.data.length = next - pos;
 668                 *current_ev = iwe_stream_add_point(info, *current_ev,
 669                                                    end_buf, &iwe, pos);
 670
 671                 pos = next;
 672         }
 673
 674         if (end > pos) {
 675                 memset(&iwe, 0, sizeof(iwe));
 676                 iwe.cmd = IWEVGENIE;
 677                 iwe.u.data.length = end - pos;
 678                 *current_ev = iwe_stream_add_point(info, *current_ev,
 679                                                    end_buf, &iwe, pos);
 680         }
 681 }
 682
 683 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 684 {
 685         unsigned long end = jiffies;
 686
 687         if (end >= start)
 688                 return jiffies_to_msecs(end - start);
 689
 690         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 691 }
 692
 693 static char *
 694 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 695               struct cfg80211_internal_bss *bss, char *current_ev,
 696               char *end_buf)
 697 {
 698         struct iw_event iwe;
 699         u8 *buf, *cfg, *p;
 700         u8 *ie = bss->pub.information_elements;
 701         int rem = bss->pub.len_information_elements, i, sig;
 702         bool ismesh = false;
 703
 704         memset(&iwe, 0, sizeof(iwe));
 705         iwe.cmd = SIOCGIWAP;
 706         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 707         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 708         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 709                                           IW_EV_ADDR_LEN);
 710
 711         memset(&iwe, 0, sizeof(iwe));
 712         iwe.cmd = SIOCGIWFREQ;
 713         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 714         iwe.u.freq.e = 0;
 715         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 716                                           IW_EV_FREQ_LEN);
 717
 718         memset(&iwe, 0, sizeof(iwe));
 719         iwe.cmd = SIOCGIWFREQ;
 720         iwe.u.freq.m = bss->pub.channel->center_freq;
 721         iwe.u.freq.e = 6;
 722         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 723                                           IW_EV_FREQ_LEN);
 724
 725         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 726                 memset(&iwe, 0, sizeof(iwe));
 727                 iwe.cmd = IWEVQUAL;
 728                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 729                                      IW_QUAL_NOISE_INVALID |
 730                                      IW_QUAL_QUAL_UPDATED;
 731                 switch (wiphy->signal_type) {
 732                 case CFG80211_SIGNAL_TYPE_MBM:
 733                         sig = bss->pub.signal / 100;
 734                         iwe.u.qual.level = sig;
 735                         iwe.u.qual.updated |= IW_QUAL_DBM;
 736                         if (sig < -110)         /* rather bad */
 737                                 sig = -110;
 738                         else if (sig > -40)     /* perfect */
 739                                 sig = -40;
 740                         /* will give a range of 0 .. 70 */
 741                         iwe.u.qual.qual = sig + 110;
 742                         break;
 743                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 744                         iwe.u.qual.level = bss->pub.signal;
 745                         /* will give range 0 .. 100 */
 746                         iwe.u.qual.qual = bss->pub.signal;
 747                         break;
 748                 default:
 749                         /* not reached */
 750                         break;
 751                 }
 752                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 753                                                   &iwe, IW_EV_QUAL_LEN);
 754         }
 755
 756         memset(&iwe, 0, sizeof(iwe));
 757         iwe.cmd = SIOCGIWENCODE;
 758         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 759                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 760         else
 761                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 762         iwe.u.data.length = 0;
 763         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 764                                           &iwe, "");
 765
 766         while (rem >= 2) {
 767                 /* invalid data */
 768                 if (ie[1] > rem - 2)
 769                         break;
 770
 771                 switch (ie[0]) {
 772                 case WLAN_EID_SSID:
 773                         memset(&iwe, 0, sizeof(iwe));
 774                         iwe.cmd = SIOCGIWESSID;
 775                         iwe.u.data.length = ie[1];
 776                         iwe.u.data.flags = 1;
 777                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 778                                                           &iwe, ie + 2);
 779                         break;
 780                 case WLAN_EID_MESH_ID:
 781                         memset(&iwe, 0, sizeof(iwe));
 782                         iwe.cmd = SIOCGIWESSID;
 783                         iwe.u.data.length = ie[1];
 784                         iwe.u.data.flags = 1;
 785                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 786                                                           &iwe, ie + 2);
 787                         break;
 788                 case WLAN_EID_MESH_CONFIG:
 789                         ismesh = true;
 790                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 791                                 break;
 792                         buf = kmalloc(50, GFP_ATOMIC);
 793                         if (!buf)
 794                                 break;
 795                         cfg = ie + 2;
 796                         memset(&iwe, 0, sizeof(iwe));
 797                         iwe.cmd = IWEVCUSTOM;
 798                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 799                         iwe.u.data.length = strlen(buf);
 800                         current_ev = iwe_stream_add_point(info, current_ev,
 801                                                           end_buf,
 802                                                           &iwe, buf);
 803                         sprintf(buf, "Path Selection Protocol ID: "
 804                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 805                                                         cfg[4]);
 806                         iwe.u.data.length = strlen(buf);
 807                         current_ev = iwe_stream_add_point(info, current_ev,
 808                                                           end_buf,
 809                                                           &iwe, buf);
 810                         sprintf(buf, "Path Selection Metric ID: "
 811                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 812                                                         cfg[8]);
 813                         iwe.u.data.length = strlen(buf);
 814                         current_ev = iwe_stream_add_point(info, current_ev,
 815                                                           end_buf,
 816                                                           &iwe, buf);
 817                         sprintf(buf, "Congestion Control Mode ID: "
 818                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 819                                                         cfg[11], cfg[12]);
 820                         iwe.u.data.length = strlen(buf);
 821                         current_ev = iwe_stream_add_point(info, current_ev,
 822                                                           end_buf,
 823                                                           &iwe, buf);
 824                         sprintf(buf, "Channel Precedence: "
 825                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 826                                                         cfg[15], cfg[16]);
 827                         iwe.u.data.length = strlen(buf);
 828                         current_ev = iwe_stream_add_point(info, current_ev,
 829                                                           end_buf,
 830                                                           &iwe, buf);
 831                         kfree(buf);
 832                         break;
 833                 case WLAN_EID_SUPP_RATES:
 834                 case WLAN_EID_EXT_SUPP_RATES:
 835                         /* display all supported rates in readable format */
 836                         p = current_ev + iwe_stream_lcp_len(info);
 837
 838                         memset(&iwe, 0, sizeof(iwe));
 839                         iwe.cmd = SIOCGIWRATE;
 840                         /* Those two flags are ignored... */
 841                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 842
 843                         for (i = 0; i < ie[1]; i++) {
 844                                 iwe.u.bitrate.value =
 845                                         ((ie[i + 2] & 0x7f) * 500000);
 846                                 p = iwe_stream_add_value(info, current_ev, p,
 847                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 848                         }
 849                         current_ev = p;
 850                         break;
 851                 }
 852                 rem -= ie[1] + 2;
 853                 ie += ie[1] + 2;
 854         }
 855
 856         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 857             || ismesh) {
 858                 memset(&iwe, 0, sizeof(iwe));
 859                 iwe.cmd = SIOCGIWMODE;
 860                 if (ismesh)
 861                         iwe.u.mode = IW_MODE_MESH;
 862                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 863                         iwe.u.mode = IW_MODE_MASTER;
 864                 else
 865                         iwe.u.mode = IW_MODE_ADHOC;
 866                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 867                                                   &iwe, IW_EV_UINT_LEN);
 868         }
 869
 870         buf = kmalloc(30, GFP_ATOMIC);
 871         if (buf) {
 872                 memset(&iwe, 0, sizeof(iwe));
 873                 iwe.cmd = IWEVCUSTOM;
 874                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 875                 iwe.u.data.length = strlen(buf);
 876                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 877                                                   &iwe, buf);
 878                 memset(&iwe, 0, sizeof(iwe));
 879                 iwe.cmd = IWEVCUSTOM;
 880                 sprintf(buf, " Last beacon: %ums ago",
 881                         elapsed_jiffies_msecs(bss->ts));
 882                 iwe.u.data.length = strlen(buf);
 883                 current_ev = iwe_stream_add_point(info, current_ev,
 884                                                   end_buf, &iwe, buf);
 885                 kfree(buf);
 886         }
 887
 888         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 889
 890         return current_ev;
 891 }
 892
 893
 894 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 895                                   struct iw_request_info *info,
 896                                   char *buf, size_t len)
 897 {
 898         char *current_ev = buf;
 899         char *end_buf = buf + len;
 900         struct cfg80211_internal_bss *bss;
 901
 902         spin_lock_bh(&dev->bss_lock);
 903         cfg80211_bss_expire(dev);
 904
 905         list_for_each_entry(bss, &dev->bss_list, list) {
 906                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 907                         spin_unlock_bh(&dev->bss_lock);
 908                         return -E2BIG;
 909                 }
 910                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 911                                            current_ev, end_buf);
 912         }
 913         spin_unlock_bh(&dev->bss_lock);
 914         return current_ev - buf;
 915 }
 916
 917
 918 int cfg80211_wext_giwscan(struct net_device *dev,
 919                           struct iw_request_info *info,
 920                           struct iw_point *data, char *extra)
 921 {
 922         struct cfg80211_registered_device *rdev;
 923         int res;
 924
 925         if (!netif_running(dev))
 926                 return -ENETDOWN;
 927
 928         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 929
 930         if (IS_ERR(rdev))
 931                 return PTR_ERR(rdev);
 932
 933         if (rdev->scan_req) {
 934                 res = -EAGAIN;
 935                 goto out;
 936         }
 937
 938         res = ieee80211_scan_results(rdev, info, extra, data->length);
 939         data->length = 0;
 940         if (res >= 0) {
 941                 data->length = res;
 942                 res = 0;
 943         }
 944
 945  out:
 946         cfg80211_unlock_rdev(rdev);
 947         return res;
 948 }
 949 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 950 #endif