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         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  32         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  33
  34         if (aborted)
  35                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  36         else
  37                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  38
  39 #ifdef CONFIG_WIRELESS_EXT
  40         if (!aborted) {
  41                 memset(&wrqu, 0, sizeof(wrqu));
  42
  43                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  44         }
  45 #endif
  46
  47         dev_put(dev);
  48
  49  out:
  50         kfree(request);
  51 }
  52 EXPORT_SYMBOL(cfg80211_scan_done);
  53
  54 static void bss_release(struct kref *ref)
  55 {
  56         struct cfg80211_internal_bss *bss;
  57
  58         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  59         if (bss->pub.free_priv)
  60                 bss->pub.free_priv(&bss->pub);
  61         kfree(bss);
  62 }
  63
  64 /* must hold dev->bss_lock! */
  65 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
  66                       unsigned long age_secs)
  67 {
  68         struct cfg80211_internal_bss *bss;
  69         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
  70
  71         list_for_each_entry(bss, &dev->bss_list, list) {
  72                 bss->ts -= age_jiffies;
  73         }
  74 }
  75
  76 /* must hold dev->bss_lock! */
  77 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
  78 {
  79         struct cfg80211_internal_bss *bss, *tmp;
  80         bool expired = false;
  81
  82         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
  83                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
  84                         continue;
  85                 list_del(&bss->list);
  86                 rb_erase(&bss->rbn, &dev->bss_tree);
  87                 kref_put(&bss->ref, bss_release);
  88                 expired = true;
  89         }
  90
  91         if (expired)
  92                 dev->bss_generation++;
  93 }
  94
  95 static u8 *find_ie(u8 num, u8 *ies, size_t len)
  96 {
  97         while (len > 2 && ies[0] != num) {
  98                 len -= ies[1] + 2;
  99                 ies += ies[1] + 2;
 100         }
 101         if (len < 2)
 102                 return NULL;
 103         if (len < 2 + ies[1])
 104                 return NULL;
 105         return ies;
 106 }
 107
 108 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 109 {
 110         const u8 *ie1 = find_ie(num, ies1, len1);
 111         const u8 *ie2 = find_ie(num, ies2, len2);
 112         int r;
 113
 114         if (!ie1 && !ie2)
 115                 return 0;
 116         if (!ie1)
 117                 return -1;
 118
 119         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 120         if (r == 0 && ie1[1] != ie2[1])
 121                 return ie2[1] - ie1[1];
 122         return r;
 123 }
 124
 125 static bool is_bss(struct cfg80211_bss *a,
 126                    const u8 *bssid,
 127                    const u8 *ssid, size_t ssid_len)
 128 {
 129         const u8 *ssidie;
 130
 131         if (bssid && compare_ether_addr(a->bssid, bssid))
 132                 return false;
 133
 134         if (!ssid)
 135                 return true;
 136
 137         ssidie = find_ie(WLAN_EID_SSID,
 138                          a->information_elements,
 139                          a->len_information_elements);
 140         if (!ssidie)
 141                 return false;
 142         if (ssidie[1] != ssid_len)
 143                 return false;
 144         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 145 }
 146
 147 static bool is_mesh(struct cfg80211_bss *a,
 148                     const u8 *meshid, size_t meshidlen,
 149                     const u8 *meshcfg)
 150 {
 151         const u8 *ie;
 152
 153         if (!is_zero_ether_addr(a->bssid))
 154                 return false;
 155
 156         ie = find_ie(WLAN_EID_MESH_ID,
 157                      a->information_elements,
 158                      a->len_information_elements);
 159         if (!ie)
 160                 return false;
 161         if (ie[1] != meshidlen)
 162                 return false;
 163         if (memcmp(ie + 2, meshid, meshidlen))
 164                 return false;
 165
 166         ie = find_ie(WLAN_EID_MESH_CONFIG,
 167                      a->information_elements,
 168                      a->len_information_elements);
 169         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 170                 return false;
 171
 172         /*
 173          * Ignore mesh capability (last two bytes of the IE) when
 174          * comparing since that may differ between stations taking
 175          * part in the same mesh.
 176          */
 177         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 178 }
 179
 180 static int cmp_bss(struct cfg80211_bss *a,
 181                    struct cfg80211_bss *b)
 182 {
 183         int r;
 184
 185         if (a->channel != b->channel)
 186                 return b->channel->center_freq - a->channel->center_freq;
 187
 188         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 189         if (r)
 190                 return r;
 191
 192         if (is_zero_ether_addr(a->bssid)) {
 193                 r = cmp_ies(WLAN_EID_MESH_ID,
 194                             a->information_elements,
 195                             a->len_information_elements,
 196                             b->information_elements,
 197                             b->len_information_elements);
 198                 if (r)
 199                         return r;
 200                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 201                                a->information_elements,
 202                                a->len_information_elements,
 203                                b->information_elements,
 204                                b->len_information_elements);
 205         }
 206
 207         return cmp_ies(WLAN_EID_SSID,
 208                        a->information_elements,
 209                        a->len_information_elements,
 210                        b->information_elements,
 211                        b->len_information_elements);
 212 }
 213
 214 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 215                                       struct ieee80211_channel *channel,
 216                                       const u8 *bssid,
 217                                       const u8 *ssid, size_t ssid_len,
 218                                       u16 capa_mask, u16 capa_val)
 219 {
 220         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 221         struct cfg80211_internal_bss *bss, *res = NULL;
 222
 223         spin_lock_bh(&dev->bss_lock);
 224
 225         list_for_each_entry(bss, &dev->bss_list, list) {
 226                 if ((bss->pub.capability & capa_mask) != capa_val)
 227                         continue;
 228                 if (channel && bss->pub.channel != channel)
 229                         continue;
 230                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 231                         res = bss;
 232                         kref_get(&res->ref);
 233                         break;
 234                 }
 235         }
 236
 237         spin_unlock_bh(&dev->bss_lock);
 238         if (!res)
 239                 return NULL;
 240         return &res->pub;
 241 }
 242 EXPORT_SYMBOL(cfg80211_get_bss);
 243
 244 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 245                                        struct ieee80211_channel *channel,
 246                                        const u8 *meshid, size_t meshidlen,
 247                                        const u8 *meshcfg)
 248 {
 249         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 250         struct cfg80211_internal_bss *bss, *res = NULL;
 251
 252         spin_lock_bh(&dev->bss_lock);
 253
 254         list_for_each_entry(bss, &dev->bss_list, list) {
 255                 if (channel && bss->pub.channel != channel)
 256                         continue;
 257                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 258                         res = bss;
 259                         kref_get(&res->ref);
 260                         break;
 261                 }
 262         }
 263
 264         spin_unlock_bh(&dev->bss_lock);
 265         if (!res)
 266                 return NULL;
 267         return &res->pub;
 268 }
 269 EXPORT_SYMBOL(cfg80211_get_mesh);
 270
 271
 272 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 273                           struct cfg80211_internal_bss *bss)
 274 {
 275         struct rb_node **p = &dev->bss_tree.rb_node;
 276         struct rb_node *parent = NULL;
 277         struct cfg80211_internal_bss *tbss;
 278         int cmp;
 279
 280         while (*p) {
 281                 parent = *p;
 282                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 283
 284                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 285
 286                 if (WARN_ON(!cmp)) {
 287                         /* will sort of leak this BSS */
 288                         return;
 289                 }
 290
 291                 if (cmp < 0)
 292                         p = &(*p)->rb_left;
 293                 else
 294                         p = &(*p)->rb_right;
 295         }
 296
 297         rb_link_node(&bss->rbn, parent, p);
 298         rb_insert_color(&bss->rbn, &dev->bss_tree);
 299 }
 300
 301 static struct cfg80211_internal_bss *
 302 rb_find_bss(struct cfg80211_registered_device *dev,
 303             struct cfg80211_internal_bss *res)
 304 {
 305         struct rb_node *n = dev->bss_tree.rb_node;
 306         struct cfg80211_internal_bss *bss;
 307         int r;
 308
 309         while (n) {
 310                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 311                 r = cmp_bss(&res->pub, &bss->pub);
 312
 313                 if (r == 0)
 314                         return bss;
 315                 else if (r < 0)
 316                         n = n->rb_left;
 317                 else
 318                         n = n->rb_right;
 319         }
 320
 321         return NULL;
 322 }
 323
 324 static struct cfg80211_internal_bss *
 325 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 326                     struct cfg80211_internal_bss *res,
 327                     bool overwrite)
 328 {
 329         struct cfg80211_internal_bss *found = NULL;
 330         const u8 *meshid, *meshcfg;
 331
 332         /*
 333          * The reference to "res" is donated to this function.
 334          */
 335
 336         if (WARN_ON(!res->pub.channel)) {
 337                 kref_put(&res->ref, bss_release);
 338                 return NULL;
 339         }
 340
 341         res->ts = jiffies;
 342
 343         if (is_zero_ether_addr(res->pub.bssid)) {
 344                 /* must be mesh, verify */
 345                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 346                                  res->pub.len_information_elements);
 347                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 348                                   res->pub.information_elements,
 349                                   res->pub.len_information_elements);
 350                 if (!meshid || !meshcfg ||
 351                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 352                         /* bogus mesh */
 353                         kref_put(&res->ref, bss_release);
 354                         return NULL;
 355                 }
 356         }
 357
 358         spin_lock_bh(&dev->bss_lock);
 359
 360         found = rb_find_bss(dev, res);
 361
 362         if (found && overwrite) {
 363                 list_replace(&found->list, &res->list);
 364                 rb_replace_node(&found->rbn, &res->rbn,
 365                                 &dev->bss_tree);
 366                 kref_put(&found->ref, bss_release);
 367                 found = res;
 368         } else if (found) {
 369                 kref_get(&found->ref);
 370                 found->pub.beacon_interval = res->pub.beacon_interval;
 371                 found->pub.tsf = res->pub.tsf;
 372                 found->pub.signal = res->pub.signal;
 373                 found->pub.capability = res->pub.capability;
 374                 found->ts = res->ts;
 375                 kref_put(&res->ref, bss_release);
 376         } else {
 377                 /* this "consumes" the reference */
 378                 list_add_tail(&res->list, &dev->bss_list);
 379                 rb_insert_bss(dev, res);
 380                 found = res;
 381         }
 382
 383         dev->bss_generation++;
 384         spin_unlock_bh(&dev->bss_lock);
 385
 386         kref_get(&found->ref);
 387         return found;
 388 }
 389
 390 struct cfg80211_bss *
 391 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 392                           struct ieee80211_channel *channel,
 393                           struct ieee80211_mgmt *mgmt, size_t len,
 394                           s32 signal, gfp_t gfp)
 395 {
 396         struct cfg80211_internal_bss *res;
 397         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 398                                       u.probe_resp.variable);
 399         bool overwrite;
 400         size_t privsz = wiphy->bss_priv_size;
 401
 402         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 403                     (signal < 0 || signal > 100)))
 404                 return NULL;
 405
 406         if (WARN_ON(!mgmt || !wiphy ||
 407                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 408                 return NULL;
 409
 410         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 411         if (!res)
 412                 return NULL;
 413
 414         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 415         res->pub.channel = channel;
 416         res->pub.signal = signal;
 417         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 418         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 419         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 420         /* point to after the private area */
 421         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 422         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 423         res->pub.len_information_elements = ielen;
 424
 425         kref_init(&res->ref);
 426
 427         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 428
 429         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 430         if (!res)
 431                 return NULL;
 432
 433         /* cfg80211_bss_update gives us a referenced result */
 434         return &res->pub;
 435 }
 436 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 437
 438 void cfg80211_put_bss(struct cfg80211_bss *pub)
 439 {
 440         struct cfg80211_internal_bss *bss;
 441
 442         if (!pub)
 443                 return;
 444
 445         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 446         kref_put(&bss->ref, bss_release);
 447 }
 448 EXPORT_SYMBOL(cfg80211_put_bss);
 449
 450 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 451 {
 452         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 453         struct cfg80211_internal_bss *bss;
 454
 455         if (WARN_ON(!pub))
 456                 return;
 457
 458         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 459
 460         spin_lock_bh(&dev->bss_lock);
 461
 462         list_del(&bss->list);
 463         rb_erase(&bss->rbn, &dev->bss_tree);
 464
 465         spin_unlock_bh(&dev->bss_lock);
 466
 467         kref_put(&bss->ref, bss_release);
 468 }
 469 EXPORT_SYMBOL(cfg80211_unlink_bss);
 470
 471 #ifdef CONFIG_WIRELESS_EXT
 472 int cfg80211_wext_siwscan(struct net_device *dev,
 473                           struct iw_request_info *info,
 474                           union iwreq_data *wrqu, char *extra)
 475 {
 476         struct cfg80211_registered_device *rdev;
 477         struct wiphy *wiphy;
 478         struct iw_scan_req *wreq = NULL;
 479         struct cfg80211_scan_request *creq;
 480         int i, err, n_channels = 0;
 481         enum ieee80211_band band;
 482
 483         if (!netif_running(dev))
 484                 return -ENETDOWN;
 485
 486         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 487
 488         if (IS_ERR(rdev))
 489                 return PTR_ERR(rdev);
 490
 491         if (rdev->scan_req) {
 492                 err = -EBUSY;
 493                 goto out;
 494         }
 495
 496         wiphy = &rdev->wiphy;
 497
 498         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 499                 if (wiphy->bands[band])
 500                         n_channels += wiphy->bands[band]->n_channels;
 501
 502         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 503                        n_channels * sizeof(void *),
 504                        GFP_ATOMIC);
 505         if (!creq) {
 506                 err = -ENOMEM;
 507                 goto out;
 508         }
 509
 510         creq->wiphy = wiphy;
 511         creq->ifidx = dev->ifindex;
 512         creq->ssids = (void *)(creq + 1);
 513         creq->channels = (void *)(creq->ssids + 1);
 514         creq->n_channels = n_channels;
 515         creq->n_ssids = 1;
 516
 517         /* all channels */
 518         i = 0;
 519         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 520                 int j;
 521                 if (!wiphy->bands[band])
 522                         continue;
 523                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 524                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 525                         i++;
 526                 }
 527         }
 528
 529         /* translate scan request */
 530         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 531                 wreq = (struct iw_scan_req *)extra;
 532
 533                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 534                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 535                                 return -EINVAL;
 536                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 537                         creq->ssids[0].ssid_len = wreq->essid_len;
 538                 }
 539                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 540                         creq->n_ssids = 0;
 541         }
 542
 543         rdev->scan_req = creq;
 544         err = rdev->ops->scan(wiphy, dev, creq);
 545         if (err) {
 546                 rdev->scan_req = NULL;
 547                 kfree(creq);
 548         }
 549  out:
 550         cfg80211_put_dev(rdev);
 551         return err;
 552 }
 553 EXPORT_SYMBOL(cfg80211_wext_siwscan);
 554
 555 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 556                                    struct cfg80211_bss *bss,
 557                                    char **current_ev, char *end_buf)
 558 {
 559         u8 *pos, *end, *next;
 560         struct iw_event iwe;
 561
 562         if (!bss->information_elements ||
 563             !bss->len_information_elements)
 564                 return;
 565
 566         /*
 567          * If needed, fragment the IEs buffer (at IE boundaries) into short
 568          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 569          */
 570         pos = bss->information_elements;
 571         end = pos + bss->len_information_elements;
 572
 573         while (end - pos > IW_GENERIC_IE_MAX) {
 574                 next = pos + 2 + pos[1];
 575                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 576                         next = next + 2 + next[1];
 577
 578                 memset(&iwe, 0, sizeof(iwe));
 579                 iwe.cmd = IWEVGENIE;
 580                 iwe.u.data.length = next - pos;
 581                 *current_ev = iwe_stream_add_point(info, *current_ev,
 582                                                    end_buf, &iwe, pos);
 583
 584                 pos = next;
 585         }
 586
 587         if (end > pos) {
 588                 memset(&iwe, 0, sizeof(iwe));
 589                 iwe.cmd = IWEVGENIE;
 590                 iwe.u.data.length = end - pos;
 591                 *current_ev = iwe_stream_add_point(info, *current_ev,
 592                                                    end_buf, &iwe, pos);
 593         }
 594 }
 595
 596 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 597 {
 598         unsigned long end = jiffies;
 599
 600         if (end >= start)
 601                 return jiffies_to_msecs(end - start);
 602
 603         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 604 }
 605
 606 static char *
 607 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 608               struct cfg80211_internal_bss *bss, char *current_ev,
 609               char *end_buf)
 610 {
 611         struct iw_event iwe;
 612         u8 *buf, *cfg, *p;
 613         u8 *ie = bss->pub.information_elements;
 614         int rem = bss->pub.len_information_elements, i, sig;
 615         bool ismesh = false;
 616
 617         memset(&iwe, 0, sizeof(iwe));
 618         iwe.cmd = SIOCGIWAP;
 619         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 620         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 621         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 622                                           IW_EV_ADDR_LEN);
 623
 624         memset(&iwe, 0, sizeof(iwe));
 625         iwe.cmd = SIOCGIWFREQ;
 626         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 627         iwe.u.freq.e = 0;
 628         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 629                                           IW_EV_FREQ_LEN);
 630
 631         memset(&iwe, 0, sizeof(iwe));
 632         iwe.cmd = SIOCGIWFREQ;
 633         iwe.u.freq.m = bss->pub.channel->center_freq;
 634         iwe.u.freq.e = 6;
 635         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 636                                           IW_EV_FREQ_LEN);
 637
 638         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 639                 memset(&iwe, 0, sizeof(iwe));
 640                 iwe.cmd = IWEVQUAL;
 641                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 642                                      IW_QUAL_NOISE_INVALID |
 643                                      IW_QUAL_QUAL_UPDATED;
 644                 switch (wiphy->signal_type) {
 645                 case CFG80211_SIGNAL_TYPE_MBM:
 646                         sig = bss->pub.signal / 100;
 647                         iwe.u.qual.level = sig;
 648                         iwe.u.qual.updated |= IW_QUAL_DBM;
 649                         if (sig < -110)         /* rather bad */
 650                                 sig = -110;
 651                         else if (sig > -40)     /* perfect */
 652                                 sig = -40;
 653                         /* will give a range of 0 .. 70 */
 654                         iwe.u.qual.qual = sig + 110;
 655                         break;
 656                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 657                         iwe.u.qual.level = bss->pub.signal;
 658                         /* will give range 0 .. 100 */
 659                         iwe.u.qual.qual = bss->pub.signal;
 660                         break;
 661                 default:
 662                         /* not reached */
 663                         break;
 664                 }
 665                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 666                                                   &iwe, IW_EV_QUAL_LEN);
 667         }
 668
 669         memset(&iwe, 0, sizeof(iwe));
 670         iwe.cmd = SIOCGIWENCODE;
 671         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 672                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 673         else
 674                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 675         iwe.u.data.length = 0;
 676         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 677                                           &iwe, "");
 678
 679         while (rem >= 2) {
 680                 /* invalid data */
 681                 if (ie[1] > rem - 2)
 682                         break;
 683
 684                 switch (ie[0]) {
 685                 case WLAN_EID_SSID:
 686                         memset(&iwe, 0, sizeof(iwe));
 687                         iwe.cmd = SIOCGIWESSID;
 688                         iwe.u.data.length = ie[1];
 689                         iwe.u.data.flags = 1;
 690                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 691                                                           &iwe, ie + 2);
 692                         break;
 693                 case WLAN_EID_MESH_ID:
 694                         memset(&iwe, 0, sizeof(iwe));
 695                         iwe.cmd = SIOCGIWESSID;
 696                         iwe.u.data.length = ie[1];
 697                         iwe.u.data.flags = 1;
 698                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 699                                                           &iwe, ie + 2);
 700                         break;
 701                 case WLAN_EID_MESH_CONFIG:
 702                         ismesh = true;
 703                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 704                                 break;
 705                         buf = kmalloc(50, GFP_ATOMIC);
 706                         if (!buf)
 707                                 break;
 708                         cfg = ie + 2;
 709                         memset(&iwe, 0, sizeof(iwe));
 710                         iwe.cmd = IWEVCUSTOM;
 711                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 712                         iwe.u.data.length = strlen(buf);
 713                         current_ev = iwe_stream_add_point(info, current_ev,
 714                                                           end_buf,
 715                                                           &iwe, buf);
 716                         sprintf(buf, "Path Selection Protocol ID: "
 717                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 718                                                         cfg[4]);
 719                         iwe.u.data.length = strlen(buf);
 720                         current_ev = iwe_stream_add_point(info, current_ev,
 721                                                           end_buf,
 722                                                           &iwe, buf);
 723                         sprintf(buf, "Path Selection Metric ID: "
 724                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 725                                                         cfg[8]);
 726                         iwe.u.data.length = strlen(buf);
 727                         current_ev = iwe_stream_add_point(info, current_ev,
 728                                                           end_buf,
 729                                                           &iwe, buf);
 730                         sprintf(buf, "Congestion Control Mode ID: "
 731                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 732                                                         cfg[11], cfg[12]);
 733                         iwe.u.data.length = strlen(buf);
 734                         current_ev = iwe_stream_add_point(info, current_ev,
 735                                                           end_buf,
 736                                                           &iwe, buf);
 737                         sprintf(buf, "Channel Precedence: "
 738                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 739                                                         cfg[15], cfg[16]);
 740                         iwe.u.data.length = strlen(buf);
 741                         current_ev = iwe_stream_add_point(info, current_ev,
 742                                                           end_buf,
 743                                                           &iwe, buf);
 744                         kfree(buf);
 745                         break;
 746                 case WLAN_EID_SUPP_RATES:
 747                 case WLAN_EID_EXT_SUPP_RATES:
 748                         /* display all supported rates in readable format */
 749                         p = current_ev + iwe_stream_lcp_len(info);
 750
 751                         memset(&iwe, 0, sizeof(iwe));
 752                         iwe.cmd = SIOCGIWRATE;
 753                         /* Those two flags are ignored... */
 754                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 755
 756                         for (i = 0; i < ie[1]; i++) {
 757                                 iwe.u.bitrate.value =
 758                                         ((ie[i + 2] & 0x7f) * 500000);
 759                                 p = iwe_stream_add_value(info, current_ev, p,
 760                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 761                         }
 762                         current_ev = p;
 763                         break;
 764                 }
 765                 rem -= ie[1] + 2;
 766                 ie += ie[1] + 2;
 767         }
 768
 769         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 770             || ismesh) {
 771                 memset(&iwe, 0, sizeof(iwe));
 772                 iwe.cmd = SIOCGIWMODE;
 773                 if (ismesh)
 774                         iwe.u.mode = IW_MODE_MESH;
 775                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 776                         iwe.u.mode = IW_MODE_MASTER;
 777                 else
 778                         iwe.u.mode = IW_MODE_ADHOC;
 779                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 780                                                   &iwe, IW_EV_UINT_LEN);
 781         }
 782
 783         buf = kmalloc(30, GFP_ATOMIC);
 784         if (buf) {
 785                 memset(&iwe, 0, sizeof(iwe));
 786                 iwe.cmd = IWEVCUSTOM;
 787                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 788                 iwe.u.data.length = strlen(buf);
 789                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 790                                                   &iwe, buf);
 791                 memset(&iwe, 0, sizeof(iwe));
 792                 iwe.cmd = IWEVCUSTOM;
 793                 sprintf(buf, " Last beacon: %ums ago",
 794                         elapsed_jiffies_msecs(bss->ts));
 795                 iwe.u.data.length = strlen(buf);
 796                 current_ev = iwe_stream_add_point(info, current_ev,
 797                                                   end_buf, &iwe, buf);
 798                 kfree(buf);
 799         }
 800
 801         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 802
 803         return current_ev;
 804 }
 805
 806
 807 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 808                                   struct iw_request_info *info,
 809                                   char *buf, size_t len)
 810 {
 811         char *current_ev = buf;
 812         char *end_buf = buf + len;
 813         struct cfg80211_internal_bss *bss;
 814
 815         spin_lock_bh(&dev->bss_lock);
 816         cfg80211_bss_expire(dev);
 817
 818         list_for_each_entry(bss, &dev->bss_list, list) {
 819                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 820                         spin_unlock_bh(&dev->bss_lock);
 821                         return -E2BIG;
 822                 }
 823                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 824                                            current_ev, end_buf);
 825         }
 826         spin_unlock_bh(&dev->bss_lock);
 827         return current_ev - buf;
 828 }
 829
 830
 831 int cfg80211_wext_giwscan(struct net_device *dev,
 832                           struct iw_request_info *info,
 833                           struct iw_point *data, char *extra)
 834 {
 835         struct cfg80211_registered_device *rdev;
 836         int res;
 837
 838         if (!netif_running(dev))
 839                 return -ENETDOWN;
 840
 841         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 842
 843         if (IS_ERR(rdev))
 844                 return PTR_ERR(rdev);
 845
 846         if (rdev->scan_req) {
 847                 res = -EAGAIN;
 848                 goto out;
 849         }
 850
 851         res = ieee80211_scan_results(rdev, info, extra, data->length);
 852         data->length = 0;
 853         if (res >= 0) {
 854                 data->length = res;
 855                 res = 0;
 856         }
 857
 858  out:
 859         cfg80211_put_dev(rdev);
 860         return res;
 861 }
 862 EXPORT_SYMBOL(cfg80211_wext_giwscan);
 863 #endif