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 #include "wext-compat.h"
  18
  19 #define IEEE80211_SCAN_RESULT_EXPIRE    (15 * HZ)
  20
  21 void __cfg80211_scan_done(struct work_struct *wk)
  22 {
  23         struct cfg80211_registered_device *rdev;
  24         struct cfg80211_scan_request *request;
  25         struct net_device *dev;
  26 #ifdef CONFIG_WIRELESS_EXT
  27         union iwreq_data wrqu;
  28 #endif
  29
  30         rdev = container_of(wk, struct cfg80211_registered_device,
  31                             scan_done_wk);
  32
  33         mutex_lock(&rdev->mtx);
  34         request = rdev->scan_req;
  35
  36         dev = request->dev;
  37
  38         /*
  39          * This must be before sending the other events!
  40          * Otherwise, wpa_supplicant gets completely confused with
  41          * wext events.
  42          */
  43         cfg80211_sme_scan_done(dev);
  44
  45         if (request->aborted)
  46                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  47         else
  48                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  49
  50 #ifdef CONFIG_WIRELESS_EXT
  51         if (!request->aborted) {
  52                 memset(&wrqu, 0, sizeof(wrqu));
  53
  54                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  55         }
  56 #endif
  57
  58         dev_put(dev);
  59
  60         cfg80211_unlock_rdev(rdev);
  61         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  62         kfree(request);
  63 }
  64
  65 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  66 {
  67         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  68
  69         request->aborted = aborted;
  70         schedule_work(&wiphy_to_dev(request->wiphy)->scan_done_wk);
  71 }
  72 EXPORT_SYMBOL(cfg80211_scan_done);
  73
  74 static void bss_release(struct kref *ref)
  75 {
  76         struct cfg80211_internal_bss *bss;
  77
  78         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  79         if (bss->pub.free_priv)
  80                 bss->pub.free_priv(&bss->pub);
  81
  82         if (bss->ies_allocated)
  83                 kfree(bss->pub.information_elements);
  84
  85         BUG_ON(atomic_read(&bss->hold));
  86
  87         kfree(bss);
  88 }
  89
  90 /* must hold dev->bss_lock! */
  91 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
  92                       unsigned long age_secs)
  93 {
  94         struct cfg80211_internal_bss *bss;
  95         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
  96
  97         list_for_each_entry(bss, &dev->bss_list, list) {
  98                 bss->ts -= age_jiffies;
  99         }
 100 }
 101
 102 /* must hold dev->bss_lock! */
 103 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 104 {
 105         struct cfg80211_internal_bss *bss, *tmp;
 106         bool expired = false;
 107
 108         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 109                 if (atomic_read(&bss->hold))
 110                         continue;
 111                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 112                         continue;
 113                 list_del(&bss->list);
 114                 rb_erase(&bss->rbn, &dev->bss_tree);
 115                 kref_put(&bss->ref, bss_release);
 116                 expired = true;
 117         }
 118
 119         if (expired)
 120                 dev->bss_generation++;
 121 }
 122
 123 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 124 {
 125         while (len > 2 && ies[0] != num) {
 126                 len -= ies[1] + 2;
 127                 ies += ies[1] + 2;
 128         }
 129         if (len < 2)
 130                 return NULL;
 131         if (len < 2 + ies[1])
 132                 return NULL;
 133         return ies;
 134 }
 135
 136 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 137 {
 138         const u8 *ie1 = find_ie(num, ies1, len1);
 139         const u8 *ie2 = find_ie(num, ies2, len2);
 140         int r;
 141
 142         if (!ie1 && !ie2)
 143                 return 0;
 144         if (!ie1 || !ie2)
 145                 return -1;
 146
 147         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 148         if (r == 0 && ie1[1] != ie2[1])
 149                 return ie2[1] - ie1[1];
 150         return r;
 151 }
 152
 153 static bool is_bss(struct cfg80211_bss *a,
 154                    const u8 *bssid,
 155                    const u8 *ssid, size_t ssid_len)
 156 {
 157         const u8 *ssidie;
 158
 159         if (bssid && compare_ether_addr(a->bssid, bssid))
 160                 return false;
 161
 162         if (!ssid)
 163                 return true;
 164
 165         ssidie = find_ie(WLAN_EID_SSID,
 166                          a->information_elements,
 167                          a->len_information_elements);
 168         if (!ssidie)
 169                 return false;
 170         if (ssidie[1] != ssid_len)
 171                 return false;
 172         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 173 }
 174
 175 static bool is_mesh(struct cfg80211_bss *a,
 176                     const u8 *meshid, size_t meshidlen,
 177                     const u8 *meshcfg)
 178 {
 179         const u8 *ie;
 180
 181         if (!is_zero_ether_addr(a->bssid))
 182                 return false;
 183
 184         ie = find_ie(WLAN_EID_MESH_ID,
 185                      a->information_elements,
 186                      a->len_information_elements);
 187         if (!ie)
 188                 return false;
 189         if (ie[1] != meshidlen)
 190                 return false;
 191         if (memcmp(ie + 2, meshid, meshidlen))
 192                 return false;
 193
 194         ie = find_ie(WLAN_EID_MESH_CONFIG,
 195                      a->information_elements,
 196                      a->len_information_elements);
 197         if (!ie)
 198                 return false;
 199         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 200                 return false;
 201
 202         /*
 203          * Ignore mesh capability (last two bytes of the IE) when
 204          * comparing since that may differ between stations taking
 205          * part in the same mesh.
 206          */
 207         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 208 }
 209
 210 static int cmp_bss(struct cfg80211_bss *a,
 211                    struct cfg80211_bss *b)
 212 {
 213         int r;
 214
 215         if (a->channel != b->channel)
 216                 return b->channel->center_freq - a->channel->center_freq;
 217
 218         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 219         if (r)
 220                 return r;
 221
 222         if (is_zero_ether_addr(a->bssid)) {
 223                 r = cmp_ies(WLAN_EID_MESH_ID,
 224                             a->information_elements,
 225                             a->len_information_elements,
 226                             b->information_elements,
 227                             b->len_information_elements);
 228                 if (r)
 229                         return r;
 230                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 231                                a->information_elements,
 232                                a->len_information_elements,
 233                                b->information_elements,
 234                                b->len_information_elements);
 235         }
 236
 237         return cmp_ies(WLAN_EID_SSID,
 238                        a->information_elements,
 239                        a->len_information_elements,
 240                        b->information_elements,
 241                        b->len_information_elements);
 242 }
 243
 244 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 245                                       struct ieee80211_channel *channel,
 246                                       const u8 *bssid,
 247                                       const u8 *ssid, size_t ssid_len,
 248                                       u16 capa_mask, u16 capa_val)
 249 {
 250         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 251         struct cfg80211_internal_bss *bss, *res = NULL;
 252
 253         spin_lock_bh(&dev->bss_lock);
 254
 255         list_for_each_entry(bss, &dev->bss_list, list) {
 256                 if ((bss->pub.capability & capa_mask) != capa_val)
 257                         continue;
 258                 if (channel && bss->pub.channel != channel)
 259                         continue;
 260                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 261                         res = bss;
 262                         kref_get(&res->ref);
 263                         break;
 264                 }
 265         }
 266
 267         spin_unlock_bh(&dev->bss_lock);
 268         if (!res)
 269                 return NULL;
 270         return &res->pub;
 271 }
 272 EXPORT_SYMBOL(cfg80211_get_bss);
 273
 274 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 275                                        struct ieee80211_channel *channel,
 276                                        const u8 *meshid, size_t meshidlen,
 277                                        const u8 *meshcfg)
 278 {
 279         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 280         struct cfg80211_internal_bss *bss, *res = NULL;
 281
 282         spin_lock_bh(&dev->bss_lock);
 283
 284         list_for_each_entry(bss, &dev->bss_list, list) {
 285                 if (channel && bss->pub.channel != channel)
 286                         continue;
 287                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 288                         res = bss;
 289                         kref_get(&res->ref);
 290                         break;
 291                 }
 292         }
 293
 294         spin_unlock_bh(&dev->bss_lock);
 295         if (!res)
 296                 return NULL;
 297         return &res->pub;
 298 }
 299 EXPORT_SYMBOL(cfg80211_get_mesh);
 300
 301
 302 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 303                           struct cfg80211_internal_bss *bss)
 304 {
 305         struct rb_node **p = &dev->bss_tree.rb_node;
 306         struct rb_node *parent = NULL;
 307         struct cfg80211_internal_bss *tbss;
 308         int cmp;
 309
 310         while (*p) {
 311                 parent = *p;
 312                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 313
 314                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 315
 316                 if (WARN_ON(!cmp)) {
 317                         /* will sort of leak this BSS */
 318                         return;
 319                 }
 320
 321                 if (cmp < 0)
 322                         p = &(*p)->rb_left;
 323                 else
 324                         p = &(*p)->rb_right;
 325         }
 326
 327         rb_link_node(&bss->rbn, parent, p);
 328         rb_insert_color(&bss->rbn, &dev->bss_tree);
 329 }
 330
 331 static struct cfg80211_internal_bss *
 332 rb_find_bss(struct cfg80211_registered_device *dev,
 333             struct cfg80211_internal_bss *res)
 334 {
 335         struct rb_node *n = dev->bss_tree.rb_node;
 336         struct cfg80211_internal_bss *bss;
 337         int r;
 338
 339         while (n) {
 340                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 341                 r = cmp_bss(&res->pub, &bss->pub);
 342
 343                 if (r == 0)
 344                         return bss;
 345                 else if (r < 0)
 346                         n = n->rb_left;
 347                 else
 348                         n = n->rb_right;
 349         }
 350
 351         return NULL;
 352 }
 353
 354 static struct cfg80211_internal_bss *
 355 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 356                     struct cfg80211_internal_bss *res,
 357                     bool overwrite)
 358 {
 359         struct cfg80211_internal_bss *found = NULL;
 360         const u8 *meshid, *meshcfg;
 361
 362         /*
 363          * The reference to "res" is donated to this function.
 364          */
 365
 366         if (WARN_ON(!res->pub.channel)) {
 367                 kref_put(&res->ref, bss_release);
 368                 return NULL;
 369         }
 370
 371         res->ts = jiffies;
 372
 373         if (is_zero_ether_addr(res->pub.bssid)) {
 374                 /* must be mesh, verify */
 375                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 376                                  res->pub.len_information_elements);
 377                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 378                                   res->pub.information_elements,
 379                                   res->pub.len_information_elements);
 380                 if (!meshid || !meshcfg ||
 381                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 382                         /* bogus mesh */
 383                         kref_put(&res->ref, bss_release);
 384                         return NULL;
 385                 }
 386         }
 387
 388         spin_lock_bh(&dev->bss_lock);
 389
 390         found = rb_find_bss(dev, res);
 391
 392         if (found) {
 393                 found->pub.beacon_interval = res->pub.beacon_interval;
 394                 found->pub.tsf = res->pub.tsf;
 395                 found->pub.signal = res->pub.signal;
 396                 found->pub.capability = res->pub.capability;
 397                 found->ts = res->ts;
 398
 399                 /* overwrite IEs */
 400                 if (overwrite) {
 401                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 402                         size_t ielen = res->pub.len_information_elements;
 403
 404                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 405                                 memcpy(found->pub.information_elements,
 406                                        res->pub.information_elements, ielen);
 407                                 found->pub.len_information_elements = ielen;
 408                         } else {
 409                                 u8 *ies = found->pub.information_elements;
 410
 411                                 if (found->ies_allocated)
 412                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 413                                 else
 414                                         ies = kmalloc(ielen, GFP_ATOMIC);
 415
 416                                 if (ies) {
 417                                         memcpy(ies, res->pub.information_elements, ielen);
 418                                         found->ies_allocated = true;
 419                                         found->pub.information_elements = ies;
 420                                         found->pub.len_information_elements = ielen;
 421                                 }
 422                         }
 423                 }
 424
 425                 kref_put(&res->ref, bss_release);
 426         } else {
 427                 /* this "consumes" the reference */
 428                 list_add_tail(&res->list, &dev->bss_list);
 429                 rb_insert_bss(dev, res);
 430                 found = res;
 431         }
 432
 433         dev->bss_generation++;
 434         spin_unlock_bh(&dev->bss_lock);
 435
 436         kref_get(&found->ref);
 437         return found;
 438 }
 439
 440 struct cfg80211_bss*
 441 cfg80211_inform_bss(struct wiphy *wiphy,
 442                     struct ieee80211_channel *channel,
 443                     const u8 *bssid,
 444                     u64 timestamp, u16 capability, u16 beacon_interval,
 445                     const u8 *ie, size_t ielen,
 446                     s32 signal, gfp_t gfp)
 447 {
 448         struct cfg80211_internal_bss *res;
 449         size_t privsz;
 450
 451         if (WARN_ON(!wiphy))
 452                 return NULL;
 453
 454         privsz = wiphy->bss_priv_size;
 455
 456         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 457                         (signal < 0 || signal > 100)))
 458                 return NULL;
 459
 460         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 461         if (!res)
 462                 return NULL;
 463
 464         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 465         res->pub.channel = channel;
 466         res->pub.signal = signal;
 467         res->pub.tsf = timestamp;
 468         res->pub.beacon_interval = beacon_interval;
 469         res->pub.capability = capability;
 470         /* point to after the private area */
 471         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 472         memcpy(res->pub.information_elements, ie, ielen);
 473         res->pub.len_information_elements = ielen;
 474
 475         kref_init(&res->ref);
 476
 477         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 478         if (!res)
 479                 return NULL;
 480
 481         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 482                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 483
 484         /* cfg80211_bss_update gives us a referenced result */
 485         return &res->pub;
 486 }
 487 EXPORT_SYMBOL(cfg80211_inform_bss);
 488
 489 struct cfg80211_bss *
 490 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 491                           struct ieee80211_channel *channel,
 492                           struct ieee80211_mgmt *mgmt, size_t len,
 493                           s32 signal, gfp_t gfp)
 494 {
 495         struct cfg80211_internal_bss *res;
 496         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 497                                       u.probe_resp.variable);
 498         bool overwrite;
 499         size_t privsz = wiphy->bss_priv_size;
 500
 501         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 502                     (signal < 0 || signal > 100)))
 503                 return NULL;
 504
 505         if (WARN_ON(!mgmt || !wiphy ||
 506                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 507                 return NULL;
 508
 509         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 510         if (!res)
 511                 return NULL;
 512
 513         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 514         res->pub.channel = channel;
 515         res->pub.signal = signal;
 516         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 517         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 518         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 519         /* point to after the private area */
 520         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 521         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 522         res->pub.len_information_elements = ielen;
 523
 524         kref_init(&res->ref);
 525
 526         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 527
 528         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 529         if (!res)
 530                 return NULL;
 531
 532         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 533                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 534
 535         /* cfg80211_bss_update gives us a referenced result */
 536         return &res->pub;
 537 }
 538 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 539
 540 void cfg80211_put_bss(struct cfg80211_bss *pub)
 541 {
 542         struct cfg80211_internal_bss *bss;
 543
 544         if (!pub)
 545                 return;
 546
 547         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 548         kref_put(&bss->ref, bss_release);
 549 }
 550 EXPORT_SYMBOL(cfg80211_put_bss);
 551
 552 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 553 {
 554         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 555         struct cfg80211_internal_bss *bss;
 556
 557         if (WARN_ON(!pub))
 558                 return;
 559
 560         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 561
 562         spin_lock_bh(&dev->bss_lock);
 563
 564         list_del(&bss->list);
 565         rb_erase(&bss->rbn, &dev->bss_tree);
 566
 567         spin_unlock_bh(&dev->bss_lock);
 568
 569         kref_put(&bss->ref, bss_release);
 570 }
 571 EXPORT_SYMBOL(cfg80211_unlink_bss);
 572
 573 #ifdef CONFIG_WIRELESS_EXT
 574 int cfg80211_wext_siwscan(struct net_device *dev,
 575                           struct iw_request_info *info,
 576                           union iwreq_data *wrqu, char *extra)
 577 {
 578         struct cfg80211_registered_device *rdev;
 579         struct wiphy *wiphy;
 580         struct iw_scan_req *wreq = NULL;
 581         struct cfg80211_scan_request *creq;
 582         int i, err, n_channels = 0;
 583         enum ieee80211_band band;
 584
 585         if (!netif_running(dev))
 586                 return -ENETDOWN;
 587
 588         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 589
 590         if (IS_ERR(rdev))
 591                 return PTR_ERR(rdev);
 592
 593         if (rdev->scan_req) {
 594                 err = -EBUSY;
 595                 goto out;
 596         }
 597
 598         wiphy = &rdev->wiphy;
 599
 600         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 601                 if (wiphy->bands[band])
 602                         n_channels += wiphy->bands[band]->n_channels;
 603
 604         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 605                        n_channels * sizeof(void *),
 606                        GFP_ATOMIC);
 607         if (!creq) {
 608                 err = -ENOMEM;
 609                 goto out;
 610         }
 611
 612         creq->wiphy = wiphy;
 613         creq->dev = dev;
 614         creq->ssids = (void *)(creq + 1);
 615         creq->channels = (void *)(creq->ssids + 1);
 616         creq->n_channels = n_channels;
 617         creq->n_ssids = 1;
 618
 619         /* all channels */
 620         i = 0;
 621         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 622                 int j;
 623                 if (!wiphy->bands[band])
 624                         continue;
 625                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 626                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 627                         i++;
 628                 }
 629         }
 630
 631         /* translate scan request */
 632         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 633                 wreq = (struct iw_scan_req *)extra;
 634
 635                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 636                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 637                                 return -EINVAL;
 638                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 639                         creq->ssids[0].ssid_len = wreq->essid_len;
 640                 }
 641                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 642                         creq->n_ssids = 0;
 643         }
 644
 645         rdev->scan_req = creq;
 646         err = rdev->ops->scan(wiphy, dev, creq);
 647         if (err) {
 648                 rdev->scan_req = NULL;
 649                 kfree(creq);
 650         } else {
 651                 nl80211_send_scan_start(rdev, dev);
 652                 dev_hold(dev);
 653         }
 654  out:
 655         cfg80211_unlock_rdev(rdev);
 656         return err;
 657 }
 658 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 659
 660 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 661                                    struct cfg80211_bss *bss,
 662                                    char **current_ev, char *end_buf)
 663 {
 664         u8 *pos, *end, *next;
 665         struct iw_event iwe;
 666
 667         if (!bss->information_elements ||
 668             !bss->len_information_elements)
 669                 return;
 670
 671         /*
 672          * If needed, fragment the IEs buffer (at IE boundaries) into short
 673          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 674          */
 675         pos = bss->information_elements;
 676         end = pos + bss->len_information_elements;
 677
 678         while (end - pos > IW_GENERIC_IE_MAX) {
 679                 next = pos + 2 + pos[1];
 680                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 681                         next = next + 2 + next[1];
 682
 683                 memset(&iwe, 0, sizeof(iwe));
 684                 iwe.cmd = IWEVGENIE;
 685                 iwe.u.data.length = next - pos;
 686                 *current_ev = iwe_stream_add_point(info, *current_ev,
 687                                                    end_buf, &iwe, pos);
 688
 689                 pos = next;
 690         }
 691
 692         if (end > pos) {
 693                 memset(&iwe, 0, sizeof(iwe));
 694                 iwe.cmd = IWEVGENIE;
 695                 iwe.u.data.length = end - pos;
 696                 *current_ev = iwe_stream_add_point(info, *current_ev,
 697                                                    end_buf, &iwe, pos);
 698         }
 699 }
 700
 701 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 702 {
 703         unsigned long end = jiffies;
 704
 705         if (end >= start)
 706                 return jiffies_to_msecs(end - start);
 707
 708         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 709 }
 710
 711 static char *
 712 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 713               struct cfg80211_internal_bss *bss, char *current_ev,
 714               char *end_buf)
 715 {
 716         struct iw_event iwe;
 717         u8 *buf, *cfg, *p;
 718         u8 *ie = bss->pub.information_elements;
 719         int rem = bss->pub.len_information_elements, i, sig;
 720         bool ismesh = false;
 721
 722         memset(&iwe, 0, sizeof(iwe));
 723         iwe.cmd = SIOCGIWAP;
 724         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 725         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 726         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 727                                           IW_EV_ADDR_LEN);
 728
 729         memset(&iwe, 0, sizeof(iwe));
 730         iwe.cmd = SIOCGIWFREQ;
 731         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 732         iwe.u.freq.e = 0;
 733         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 734                                           IW_EV_FREQ_LEN);
 735
 736         memset(&iwe, 0, sizeof(iwe));
 737         iwe.cmd = SIOCGIWFREQ;
 738         iwe.u.freq.m = bss->pub.channel->center_freq;
 739         iwe.u.freq.e = 6;
 740         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 741                                           IW_EV_FREQ_LEN);
 742
 743         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 744                 memset(&iwe, 0, sizeof(iwe));
 745                 iwe.cmd = IWEVQUAL;
 746                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 747                                      IW_QUAL_NOISE_INVALID |
 748                                      IW_QUAL_QUAL_UPDATED;
 749                 switch (wiphy->signal_type) {
 750                 case CFG80211_SIGNAL_TYPE_MBM:
 751                         sig = bss->pub.signal / 100;
 752                         iwe.u.qual.level = sig;
 753                         iwe.u.qual.updated |= IW_QUAL_DBM;
 754                         if (sig < -110)         /* rather bad */
 755                                 sig = -110;
 756                         else if (sig > -40)     /* perfect */
 757                                 sig = -40;
 758                         /* will give a range of 0 .. 70 */
 759                         iwe.u.qual.qual = sig + 110;
 760                         break;
 761                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 762                         iwe.u.qual.level = bss->pub.signal;
 763                         /* will give range 0 .. 100 */
 764                         iwe.u.qual.qual = bss->pub.signal;
 765                         break;
 766                 default:
 767                         /* not reached */
 768                         break;
 769                 }
 770                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 771                                                   &iwe, IW_EV_QUAL_LEN);
 772         }
 773
 774         memset(&iwe, 0, sizeof(iwe));
 775         iwe.cmd = SIOCGIWENCODE;
 776         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 777                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 778         else
 779                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 780         iwe.u.data.length = 0;
 781         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 782                                           &iwe, "");
 783
 784         while (rem >= 2) {
 785                 /* invalid data */
 786                 if (ie[1] > rem - 2)
 787                         break;
 788
 789                 switch (ie[0]) {
 790                 case WLAN_EID_SSID:
 791                         memset(&iwe, 0, sizeof(iwe));
 792                         iwe.cmd = SIOCGIWESSID;
 793                         iwe.u.data.length = ie[1];
 794                         iwe.u.data.flags = 1;
 795                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 796                                                           &iwe, ie + 2);
 797                         break;
 798                 case WLAN_EID_MESH_ID:
 799                         memset(&iwe, 0, sizeof(iwe));
 800                         iwe.cmd = SIOCGIWESSID;
 801                         iwe.u.data.length = ie[1];
 802                         iwe.u.data.flags = 1;
 803                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 804                                                           &iwe, ie + 2);
 805                         break;
 806                 case WLAN_EID_MESH_CONFIG:
 807                         ismesh = true;
 808                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 809                                 break;
 810                         buf = kmalloc(50, GFP_ATOMIC);
 811                         if (!buf)
 812                                 break;
 813                         cfg = ie + 2;
 814                         memset(&iwe, 0, sizeof(iwe));
 815                         iwe.cmd = IWEVCUSTOM;
 816                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 817                         iwe.u.data.length = strlen(buf);
 818                         current_ev = iwe_stream_add_point(info, current_ev,
 819                                                           end_buf,
 820                                                           &iwe, buf);
 821                         sprintf(buf, "Path Selection Protocol ID: "
 822                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 823                                                         cfg[4]);
 824                         iwe.u.data.length = strlen(buf);
 825                         current_ev = iwe_stream_add_point(info, current_ev,
 826                                                           end_buf,
 827                                                           &iwe, buf);
 828                         sprintf(buf, "Path Selection Metric ID: "
 829                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 830                                                         cfg[8]);
 831                         iwe.u.data.length = strlen(buf);
 832                         current_ev = iwe_stream_add_point(info, current_ev,
 833                                                           end_buf,
 834                                                           &iwe, buf);
 835                         sprintf(buf, "Congestion Control Mode ID: "
 836                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 837                                                         cfg[11], cfg[12]);
 838                         iwe.u.data.length = strlen(buf);
 839                         current_ev = iwe_stream_add_point(info, current_ev,
 840                                                           end_buf,
 841                                                           &iwe, buf);
 842                         sprintf(buf, "Channel Precedence: "
 843                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 844                                                         cfg[15], cfg[16]);
 845                         iwe.u.data.length = strlen(buf);
 846                         current_ev = iwe_stream_add_point(info, current_ev,
 847                                                           end_buf,
 848                                                           &iwe, buf);
 849                         kfree(buf);
 850                         break;
 851                 case WLAN_EID_SUPP_RATES:
 852                 case WLAN_EID_EXT_SUPP_RATES:
 853                         /* display all supported rates in readable format */
 854                         p = current_ev + iwe_stream_lcp_len(info);
 855
 856                         memset(&iwe, 0, sizeof(iwe));
 857                         iwe.cmd = SIOCGIWRATE;
 858                         /* Those two flags are ignored... */
 859                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 860
 861                         for (i = 0; i < ie[1]; i++) {
 862                                 iwe.u.bitrate.value =
 863                                         ((ie[i + 2] & 0x7f) * 500000);
 864                                 p = iwe_stream_add_value(info, current_ev, p,
 865                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 866                         }
 867                         current_ev = p;
 868                         break;
 869                 }
 870                 rem -= ie[1] + 2;
 871                 ie += ie[1] + 2;
 872         }
 873
 874         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 875             || ismesh) {
 876                 memset(&iwe, 0, sizeof(iwe));
 877                 iwe.cmd = SIOCGIWMODE;
 878                 if (ismesh)
 879                         iwe.u.mode = IW_MODE_MESH;
 880                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 881                         iwe.u.mode = IW_MODE_MASTER;
 882                 else
 883                         iwe.u.mode = IW_MODE_ADHOC;
 884                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 885                                                   &iwe, IW_EV_UINT_LEN);
 886         }
 887
 888         buf = kmalloc(30, GFP_ATOMIC);
 889         if (buf) {
 890                 memset(&iwe, 0, sizeof(iwe));
 891                 iwe.cmd = IWEVCUSTOM;
 892                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 893                 iwe.u.data.length = strlen(buf);
 894                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 895                                                   &iwe, buf);
 896                 memset(&iwe, 0, sizeof(iwe));
 897                 iwe.cmd = IWEVCUSTOM;
 898                 sprintf(buf, " Last beacon: %ums ago",
 899                         elapsed_jiffies_msecs(bss->ts));
 900                 iwe.u.data.length = strlen(buf);
 901                 current_ev = iwe_stream_add_point(info, current_ev,
 902                                                   end_buf, &iwe, buf);
 903                 kfree(buf);
 904         }
 905
 906         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 907
 908         return current_ev;
 909 }
 910
 911
 912 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 913                                   struct iw_request_info *info,
 914                                   char *buf, size_t len)
 915 {
 916         char *current_ev = buf;
 917         char *end_buf = buf + len;
 918         struct cfg80211_internal_bss *bss;
 919
 920         spin_lock_bh(&dev->bss_lock);
 921         cfg80211_bss_expire(dev);
 922
 923         list_for_each_entry(bss, &dev->bss_list, list) {
 924                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 925                         spin_unlock_bh(&dev->bss_lock);
 926                         return -E2BIG;
 927                 }
 928                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 929                                            current_ev, end_buf);
 930         }
 931         spin_unlock_bh(&dev->bss_lock);
 932         return current_ev - buf;
 933 }
 934
 935
 936 int cfg80211_wext_giwscan(struct net_device *dev,
 937                           struct iw_request_info *info,
 938                           struct iw_point *data, char *extra)
 939 {
 940         struct cfg80211_registered_device *rdev;
 941         int res;
 942
 943         if (!netif_running(dev))
 944                 return -ENETDOWN;
 945
 946         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 947
 948         if (IS_ERR(rdev))
 949                 return PTR_ERR(rdev);
 950
 951         if (rdev->scan_req) {
 952                 res = -EAGAIN;
 953                 goto out;
 954         }
 955
 956         res = ieee80211_scan_results(rdev, info, extra, data->length);
 957         data->length = 0;
 958         if (res >= 0) {
 959                 data->length = res;
 960                 res = 0;
 961         }
 962
 963  out:
 964         cfg80211_unlock_rdev(rdev);
 965         return res;
 966 }
 967 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 968 #endif