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/slab.h>
   8 #include <linux/module.h>
   9 #include <linux/netdevice.h>
  10 #include <linux/wireless.h>
  11 #include <linux/nl80211.h>
  12 #include <linux/etherdevice.h>
  13 #include <net/arp.h>
  14 #include <net/cfg80211.h>
  15 #include <net/iw_handler.h>
  16 #include "core.h"
  17 #include "nl80211.h"
  18 #include "wext-compat.h"
  19
  20 #define IEEE80211_SCAN_RESULT_EXPIRE    (15 * HZ)
  21
  22 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
  23 {
  24         struct cfg80211_scan_request *request;
  25         struct net_device *dev;
  26 #ifdef CONFIG_CFG80211_WEXT
  27         union iwreq_data wrqu;
  28 #endif
  29
  30         ASSERT_RDEV_LOCK(rdev);
  31
  32         request = rdev->scan_req;
  33
  34         if (!request)
  35                 return;
  36
  37         dev = request->dev;
  38
  39         /*
  40          * This must be before sending the other events!
  41          * Otherwise, wpa_supplicant gets completely confused with
  42          * wext events.
  43          */
  44         cfg80211_sme_scan_done(dev);
  45
  46         if (request->aborted)
  47                 nl80211_send_scan_aborted(rdev, dev);
  48         else
  49                 nl80211_send_scan_done(rdev, dev);
  50
  51 #ifdef CONFIG_CFG80211_WEXT
  52         if (!request->aborted) {
  53                 memset(&wrqu, 0, sizeof(wrqu));
  54
  55                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  56         }
  57 #endif
  58
  59         dev_put(dev);
  60
  61         rdev->scan_req = NULL;
  62
  63         /*
  64          * OK. If this is invoked with "leak" then we can't
  65          * free this ... but we've cleaned it up anyway. The
  66          * driver failed to call the scan_done callback, so
  67          * all bets are off, it might still be trying to use
  68          * the scan request or not ... if it accesses the dev
  69          * in there (it shouldn't anyway) then it may crash.
  70          */
  71         if (!leak)
  72                 kfree(request);
  73 }
  74
  75 void __cfg80211_scan_done(struct work_struct *wk)
  76 {
  77         struct cfg80211_registered_device *rdev;
  78
  79         rdev = container_of(wk, struct cfg80211_registered_device,
  80                             scan_done_wk);
  81
  82         cfg80211_lock_rdev(rdev);
  83         ___cfg80211_scan_done(rdev, false);
  84         cfg80211_unlock_rdev(rdev);
  85 }
  86
  87 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  88 {
  89         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  90
  91         request->aborted = aborted;
  92         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
  93 }
  94 EXPORT_SYMBOL(cfg80211_scan_done);
  95
  96 static void bss_release(struct kref *ref)
  97 {
  98         struct cfg80211_internal_bss *bss;
  99
 100         bss = container_of(ref, struct cfg80211_internal_bss, ref);
 101         if (bss->pub.free_priv)
 102                 bss->pub.free_priv(&bss->pub);
 103
 104         if (bss->beacon_ies_allocated)
 105                 kfree(bss->pub.beacon_ies);
 106         if (bss->proberesp_ies_allocated)
 107                 kfree(bss->pub.proberesp_ies);
 108
 109         BUG_ON(atomic_read(&bss->hold));
 110
 111         kfree(bss);
 112 }
 113
 114 /* must hold dev->bss_lock! */
 115 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 116                       unsigned long age_secs)
 117 {
 118         struct cfg80211_internal_bss *bss;
 119         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 120
 121         list_for_each_entry(bss, &dev->bss_list, list) {
 122                 bss->ts -= age_jiffies;
 123         }
 124 }
 125
 126 /* must hold dev->bss_lock! */
 127 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 128 {
 129         struct cfg80211_internal_bss *bss, *tmp;
 130         bool expired = false;
 131
 132         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 133                 if (atomic_read(&bss->hold))
 134                         continue;
 135                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 136                         continue;
 137                 list_del(&bss->list);
 138                 rb_erase(&bss->rbn, &dev->bss_tree);
 139                 kref_put(&bss->ref, bss_release);
 140                 expired = true;
 141         }
 142
 143         if (expired)
 144                 dev->bss_generation++;
 145 }
 146
 147 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 148 {
 149         while (len > 2 && ies[0] != eid) {
 150                 len -= ies[1] + 2;
 151                 ies += ies[1] + 2;
 152         }
 153         if (len < 2)
 154                 return NULL;
 155         if (len < 2 + ies[1])
 156                 return NULL;
 157         return ies;
 158 }
 159 EXPORT_SYMBOL(cfg80211_find_ie);
 160
 161 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 162 {
 163         const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
 164         const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
 165         int r;
 166
 167         if (!ie1 && !ie2)
 168                 return 0;
 169         if (!ie1 || !ie2)
 170                 return -1;
 171
 172         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 173         if (r == 0 && ie1[1] != ie2[1])
 174                 return ie2[1] - ie1[1];
 175         return r;
 176 }
 177
 178 static bool is_bss(struct cfg80211_bss *a,
 179                    const u8 *bssid,
 180                    const u8 *ssid, size_t ssid_len)
 181 {
 182         const u8 *ssidie;
 183
 184         if (bssid && compare_ether_addr(a->bssid, bssid))
 185                 return false;
 186
 187         if (!ssid)
 188                 return true;
 189
 190         ssidie = cfg80211_find_ie(WLAN_EID_SSID,
 191                                   a->information_elements,
 192                                   a->len_information_elements);
 193         if (!ssidie)
 194                 return false;
 195         if (ssidie[1] != ssid_len)
 196                 return false;
 197         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 198 }
 199
 200 static bool is_mesh(struct cfg80211_bss *a,
 201                     const u8 *meshid, size_t meshidlen,
 202                     const u8 *meshcfg)
 203 {
 204         const u8 *ie;
 205
 206         if (!is_zero_ether_addr(a->bssid))
 207                 return false;
 208
 209         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 210                               a->information_elements,
 211                               a->len_information_elements);
 212         if (!ie)
 213                 return false;
 214         if (ie[1] != meshidlen)
 215                 return false;
 216         if (memcmp(ie + 2, meshid, meshidlen))
 217                 return false;
 218
 219         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 220                               a->information_elements,
 221                               a->len_information_elements);
 222         if (!ie)
 223                 return false;
 224         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 225                 return false;
 226
 227         /*
 228          * Ignore mesh capability (last two bytes of the IE) when
 229          * comparing since that may differ between stations taking
 230          * part in the same mesh.
 231          */
 232         return memcmp(ie + 2, meshcfg,
 233             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
 234 }
 235
 236 static int cmp_bss(struct cfg80211_bss *a,
 237                    struct cfg80211_bss *b)
 238 {
 239         int r;
 240
 241         if (a->channel != b->channel)
 242                 return b->channel->center_freq - a->channel->center_freq;
 243
 244         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 245         if (r)
 246                 return r;
 247
 248         if (is_zero_ether_addr(a->bssid)) {
 249                 r = cmp_ies(WLAN_EID_MESH_ID,
 250                             a->information_elements,
 251                             a->len_information_elements,
 252                             b->information_elements,
 253                             b->len_information_elements);
 254                 if (r)
 255                         return r;
 256                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 257                                a->information_elements,
 258                                a->len_information_elements,
 259                                b->information_elements,
 260                                b->len_information_elements);
 261         }
 262
 263         return cmp_ies(WLAN_EID_SSID,
 264                        a->information_elements,
 265                        a->len_information_elements,
 266                        b->information_elements,
 267                        b->len_information_elements);
 268 }
 269
 270 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 271                                       struct ieee80211_channel *channel,
 272                                       const u8 *bssid,
 273                                       const u8 *ssid, size_t ssid_len,
 274                                       u16 capa_mask, u16 capa_val)
 275 {
 276         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 277         struct cfg80211_internal_bss *bss, *res = NULL;
 278         unsigned long now = jiffies;
 279
 280         spin_lock_bh(&dev->bss_lock);
 281
 282         list_for_each_entry(bss, &dev->bss_list, list) {
 283                 if ((bss->pub.capability & capa_mask) != capa_val)
 284                         continue;
 285                 if (channel && bss->pub.channel != channel)
 286                         continue;
 287                 /* Don't get expired BSS structs */
 288                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 289                     !atomic_read(&bss->hold))
 290                         continue;
 291                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 292                         res = bss;
 293                         kref_get(&res->ref);
 294                         break;
 295                 }
 296         }
 297
 298         spin_unlock_bh(&dev->bss_lock);
 299         if (!res)
 300                 return NULL;
 301         return &res->pub;
 302 }
 303 EXPORT_SYMBOL(cfg80211_get_bss);
 304
 305 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 306                                        struct ieee80211_channel *channel,
 307                                        const u8 *meshid, size_t meshidlen,
 308                                        const u8 *meshcfg)
 309 {
 310         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 311         struct cfg80211_internal_bss *bss, *res = NULL;
 312
 313         spin_lock_bh(&dev->bss_lock);
 314
 315         list_for_each_entry(bss, &dev->bss_list, list) {
 316                 if (channel && bss->pub.channel != channel)
 317                         continue;
 318                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 319                         res = bss;
 320                         kref_get(&res->ref);
 321                         break;
 322                 }
 323         }
 324
 325         spin_unlock_bh(&dev->bss_lock);
 326         if (!res)
 327                 return NULL;
 328         return &res->pub;
 329 }
 330 EXPORT_SYMBOL(cfg80211_get_mesh);
 331
 332
 333 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 334                           struct cfg80211_internal_bss *bss)
 335 {
 336         struct rb_node **p = &dev->bss_tree.rb_node;
 337         struct rb_node *parent = NULL;
 338         struct cfg80211_internal_bss *tbss;
 339         int cmp;
 340
 341         while (*p) {
 342                 parent = *p;
 343                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 344
 345                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 346
 347                 if (WARN_ON(!cmp)) {
 348                         /* will sort of leak this BSS */
 349                         return;
 350                 }
 351
 352                 if (cmp < 0)
 353                         p = &(*p)->rb_left;
 354                 else
 355                         p = &(*p)->rb_right;
 356         }
 357
 358         rb_link_node(&bss->rbn, parent, p);
 359         rb_insert_color(&bss->rbn, &dev->bss_tree);
 360 }
 361
 362 static struct cfg80211_internal_bss *
 363 rb_find_bss(struct cfg80211_registered_device *dev,
 364             struct cfg80211_internal_bss *res)
 365 {
 366         struct rb_node *n = dev->bss_tree.rb_node;
 367         struct cfg80211_internal_bss *bss;
 368         int r;
 369
 370         while (n) {
 371                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 372                 r = cmp_bss(&res->pub, &bss->pub);
 373
 374                 if (r == 0)
 375                         return bss;
 376                 else if (r < 0)
 377                         n = n->rb_left;
 378                 else
 379                         n = n->rb_right;
 380         }
 381
 382         return NULL;
 383 }
 384
 385 static struct cfg80211_internal_bss *
 386 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 387                     struct cfg80211_internal_bss *res)
 388 {
 389         struct cfg80211_internal_bss *found = NULL;
 390         const u8 *meshid, *meshcfg;
 391
 392         /*
 393          * The reference to "res" is donated to this function.
 394          */
 395
 396         if (WARN_ON(!res->pub.channel)) {
 397                 kref_put(&res->ref, bss_release);
 398                 return NULL;
 399         }
 400
 401         res->ts = jiffies;
 402
 403         if (is_zero_ether_addr(res->pub.bssid)) {
 404                 /* must be mesh, verify */
 405                 meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
 406                                           res->pub.information_elements,
 407                                           res->pub.len_information_elements);
 408                 meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 409                                            res->pub.information_elements,
 410                                            res->pub.len_information_elements);
 411                 if (!meshid || !meshcfg ||
 412                     meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
 413                         /* bogus mesh */
 414                         kref_put(&res->ref, bss_release);
 415                         return NULL;
 416                 }
 417         }
 418
 419         spin_lock_bh(&dev->bss_lock);
 420
 421         found = rb_find_bss(dev, res);
 422
 423         if (found) {
 424                 found->pub.beacon_interval = res->pub.beacon_interval;
 425                 found->pub.tsf = res->pub.tsf;
 426                 found->pub.signal = res->pub.signal;
 427                 found->pub.capability = res->pub.capability;
 428                 found->ts = res->ts;
 429
 430                 /* Update IEs */
 431                 if (res->pub.proberesp_ies) {
 432                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 433                         size_t ielen = res->pub.len_proberesp_ies;
 434
 435                         if (found->pub.proberesp_ies &&
 436                             !found->proberesp_ies_allocated &&
 437                             ksize(found) >= used + ielen) {
 438                                 memcpy(found->pub.proberesp_ies,
 439                                        res->pub.proberesp_ies, ielen);
 440                                 found->pub.len_proberesp_ies = ielen;
 441                         } else {
 442                                 u8 *ies = found->pub.proberesp_ies;
 443
 444                                 if (found->proberesp_ies_allocated)
 445                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 446                                 else
 447                                         ies = kmalloc(ielen, GFP_ATOMIC);
 448
 449                                 if (ies) {
 450                                         memcpy(ies, res->pub.proberesp_ies,
 451                                                ielen);
 452                                         found->proberesp_ies_allocated = true;
 453                                         found->pub.proberesp_ies = ies;
 454                                         found->pub.len_proberesp_ies = ielen;
 455                                 }
 456                         }
 457
 458                         /* Override possible earlier Beacon frame IEs */
 459                         found->pub.information_elements =
 460                                 found->pub.proberesp_ies;
 461                         found->pub.len_information_elements =
 462                                 found->pub.len_proberesp_ies;
 463                 }
 464                 if (res->pub.beacon_ies) {
 465                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 466                         size_t ielen = res->pub.len_beacon_ies;
 467
 468                         if (found->pub.beacon_ies &&
 469                             !found->beacon_ies_allocated &&
 470                             ksize(found) >= used + ielen) {
 471                                 memcpy(found->pub.beacon_ies,
 472                                        res->pub.beacon_ies, ielen);
 473                                 found->pub.len_beacon_ies = ielen;
 474                         } else {
 475                                 u8 *ies = found->pub.beacon_ies;
 476
 477                                 if (found->beacon_ies_allocated)
 478                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 479                                 else
 480                                         ies = kmalloc(ielen, GFP_ATOMIC);
 481
 482                                 if (ies) {
 483                                         memcpy(ies, res->pub.beacon_ies,
 484                                                ielen);
 485                                         found->beacon_ies_allocated = true;
 486                                         found->pub.beacon_ies = ies;
 487                                         found->pub.len_beacon_ies = ielen;
 488                                 }
 489                         }
 490                 }
 491
 492                 kref_put(&res->ref, bss_release);
 493         } else {
 494                 /* this "consumes" the reference */
 495                 list_add_tail(&res->list, &dev->bss_list);
 496                 rb_insert_bss(dev, res);
 497                 found = res;
 498         }
 499
 500         dev->bss_generation++;
 501         spin_unlock_bh(&dev->bss_lock);
 502
 503         kref_get(&found->ref);
 504         return found;
 505 }
 506
 507 struct cfg80211_bss*
 508 cfg80211_inform_bss(struct wiphy *wiphy,
 509                     struct ieee80211_channel *channel,
 510                     const u8 *bssid,
 511                     u64 timestamp, u16 capability, u16 beacon_interval,
 512                     const u8 *ie, size_t ielen,
 513                     s32 signal, gfp_t gfp)
 514 {
 515         struct cfg80211_internal_bss *res;
 516         size_t privsz;
 517
 518         if (WARN_ON(!wiphy))
 519                 return NULL;
 520
 521         privsz = wiphy->bss_priv_size;
 522
 523         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 524                         (signal < 0 || signal > 100)))
 525                 return NULL;
 526
 527         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 528         if (!res)
 529                 return NULL;
 530
 531         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 532         res->pub.channel = channel;
 533         res->pub.signal = signal;
 534         res->pub.tsf = timestamp;
 535         res->pub.beacon_interval = beacon_interval;
 536         res->pub.capability = capability;
 537         /*
 538          * Since we do not know here whether the IEs are from a Beacon or Probe
 539          * Response frame, we need to pick one of the options and only use it
 540          * with the driver that does not provide the full Beacon/Probe Response
 541          * frame. Use Beacon frame pointer to avoid indicating that this should
 542          * override the information_elements pointer should we have received an
 543          * earlier indication of Probe Response data.
 544          *
 545          * The initial buffer for the IEs is allocated with the BSS entry and
 546          * is located after the private area.
 547          */
 548         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
 549         memcpy(res->pub.beacon_ies, ie, ielen);
 550         res->pub.len_beacon_ies = ielen;
 551         res->pub.information_elements = res->pub.beacon_ies;
 552         res->pub.len_information_elements = res->pub.len_beacon_ies;
 553
 554         kref_init(&res->ref);
 555
 556         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 557         if (!res)
 558                 return NULL;
 559
 560         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 561                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 562
 563         /* cfg80211_bss_update gives us a referenced result */
 564         return &res->pub;
 565 }
 566 EXPORT_SYMBOL(cfg80211_inform_bss);
 567
 568 struct cfg80211_bss *
 569 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 570                           struct ieee80211_channel *channel,
 571                           struct ieee80211_mgmt *mgmt, size_t len,
 572                           s32 signal, gfp_t gfp)
 573 {
 574         struct cfg80211_internal_bss *res;
 575         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 576                                       u.probe_resp.variable);
 577         size_t privsz = wiphy->bss_priv_size;
 578
 579         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 580                     (signal < 0 || signal > 100)))
 581                 return NULL;
 582
 583         if (WARN_ON(!mgmt || !wiphy ||
 584                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 585                 return NULL;
 586
 587         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 588         if (!res)
 589                 return NULL;
 590
 591         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 592         res->pub.channel = channel;
 593         res->pub.signal = signal;
 594         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 595         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 596         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 597         /*
 598          * The initial buffer for the IEs is allocated with the BSS entry and
 599          * is located after the private area.
 600          */
 601         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 602                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
 603                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
 604                        ielen);
 605                 res->pub.len_proberesp_ies = ielen;
 606                 res->pub.information_elements = res->pub.proberesp_ies;
 607                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
 608         } else {
 609                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
 610                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
 611                 res->pub.len_beacon_ies = ielen;
 612                 res->pub.information_elements = res->pub.beacon_ies;
 613                 res->pub.len_information_elements = res->pub.len_beacon_ies;
 614         }
 615
 616         kref_init(&res->ref);
 617
 618         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 619         if (!res)
 620                 return NULL;
 621
 622         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 623                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 624
 625         /* cfg80211_bss_update gives us a referenced result */
 626         return &res->pub;
 627 }
 628 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 629
 630 void cfg80211_put_bss(struct cfg80211_bss *pub)
 631 {
 632         struct cfg80211_internal_bss *bss;
 633
 634         if (!pub)
 635                 return;
 636
 637         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 638         kref_put(&bss->ref, bss_release);
 639 }
 640 EXPORT_SYMBOL(cfg80211_put_bss);
 641
 642 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 643 {
 644         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 645         struct cfg80211_internal_bss *bss;
 646
 647         if (WARN_ON(!pub))
 648                 return;
 649
 650         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 651
 652         spin_lock_bh(&dev->bss_lock);
 653         if (!list_empty(&bss->list)) {
 654                 list_del_init(&bss->list);
 655                 dev->bss_generation++;
 656                 rb_erase(&bss->rbn, &dev->bss_tree);
 657
 658                 kref_put(&bss->ref, bss_release);
 659         }
 660         spin_unlock_bh(&dev->bss_lock);
 661 }
 662 EXPORT_SYMBOL(cfg80211_unlink_bss);
 663
 664 #ifdef CONFIG_CFG80211_WEXT
 665 int cfg80211_wext_siwscan(struct net_device *dev,
 666                           struct iw_request_info *info,
 667                           union iwreq_data *wrqu, char *extra)
 668 {
 669         struct cfg80211_registered_device *rdev;
 670         struct wiphy *wiphy;
 671         struct iw_scan_req *wreq = NULL;
 672         struct cfg80211_scan_request *creq = NULL;
 673         int i, err, n_channels = 0;
 674         enum ieee80211_band band;
 675
 676         if (!netif_running(dev))
 677                 return -ENETDOWN;
 678
 679         if (wrqu->data.length == sizeof(struct iw_scan_req))
 680                 wreq = (struct iw_scan_req *)extra;
 681
 682         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 683
 684         if (IS_ERR(rdev))
 685                 return PTR_ERR(rdev);
 686
 687         if (rdev->scan_req) {
 688                 err = -EBUSY;
 689                 goto out;
 690         }
 691
 692         wiphy = &rdev->wiphy;
 693
 694         /* Determine number of channels, needed to allocate creq */
 695         if (wreq && wreq->num_channels)
 696                 n_channels = wreq->num_channels;
 697         else {
 698                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 699                         if (wiphy->bands[band])
 700                                 n_channels += wiphy->bands[band]->n_channels;
 701         }
 702
 703         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 704                        n_channels * sizeof(void *),
 705                        GFP_ATOMIC);
 706         if (!creq) {
 707                 err = -ENOMEM;
 708                 goto out;
 709         }
 710
 711         creq->wiphy = wiphy;
 712         creq->dev = dev;
 713         /* SSIDs come after channels */
 714         creq->ssids = (void *)&creq->channels[n_channels];
 715         creq->n_channels = n_channels;
 716         creq->n_ssids = 1;
 717
 718         /* translate "Scan on frequencies" request */
 719         i = 0;
 720         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 721                 int j;
 722
 723                 if (!wiphy->bands[band])
 724                         continue;
 725
 726                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 727                         /* ignore disabled channels */
 728                         if (wiphy->bands[band]->channels[j].flags &
 729                                                 IEEE80211_CHAN_DISABLED)
 730                                 continue;
 731
 732                         /* If we have a wireless request structure and the
 733                          * wireless request specifies frequencies, then search
 734                          * for the matching hardware channel.
 735                          */
 736                         if (wreq && wreq->num_channels) {
 737                                 int k;
 738                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 739                                 for (k = 0; k < wreq->num_channels; k++) {
 740                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 741                                         if (wext_freq == wiphy_freq)
 742                                                 goto wext_freq_found;
 743                                 }
 744                                 goto wext_freq_not_found;
 745                         }
 746
 747                 wext_freq_found:
 748                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 749                         i++;
 750                 wext_freq_not_found: ;
 751                 }
 752         }
 753         /* No channels found? */
 754         if (!i) {
 755                 err = -EINVAL;
 756                 goto out;
 757         }
 758
 759         /* Set real number of channels specified in creq->channels[] */
 760         creq->n_channels = i;
 761
 762         /* translate "Scan for SSID" request */
 763         if (wreq) {
 764                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 765                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
 766                                 err = -EINVAL;
 767                                 goto out;
 768                         }
 769                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 770                         creq->ssids[0].ssid_len = wreq->essid_len;
 771                 }
 772                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 773                         creq->n_ssids = 0;
 774         }
 775
 776         rdev->scan_req = creq;
 777         err = rdev->ops->scan(wiphy, dev, creq);
 778         if (err) {
 779                 rdev->scan_req = NULL;
 780                 /* creq will be freed below */
 781         } else {
 782                 nl80211_send_scan_start(rdev, dev);
 783                 /* creq now owned by driver */
 784                 creq = NULL;
 785                 dev_hold(dev);
 786         }
 787  out:
 788         kfree(creq);
 789         cfg80211_unlock_rdev(rdev);
 790         return err;
 791 }
 792 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 793
 794 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 795                                    struct cfg80211_bss *bss,
 796                                    char **current_ev, char *end_buf)
 797 {
 798         u8 *pos, *end, *next;
 799         struct iw_event iwe;
 800
 801         if (!bss->information_elements ||
 802             !bss->len_information_elements)
 803                 return;
 804
 805         /*
 806          * If needed, fragment the IEs buffer (at IE boundaries) into short
 807          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 808          */
 809         pos = bss->information_elements;
 810         end = pos + bss->len_information_elements;
 811
 812         while (end - pos > IW_GENERIC_IE_MAX) {
 813                 next = pos + 2 + pos[1];
 814                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 815                         next = next + 2 + next[1];
 816
 817                 memset(&iwe, 0, sizeof(iwe));
 818                 iwe.cmd = IWEVGENIE;
 819                 iwe.u.data.length = next - pos;
 820                 *current_ev = iwe_stream_add_point(info, *current_ev,
 821                                                    end_buf, &iwe, pos);
 822
 823                 pos = next;
 824         }
 825
 826         if (end > pos) {
 827                 memset(&iwe, 0, sizeof(iwe));
 828                 iwe.cmd = IWEVGENIE;
 829                 iwe.u.data.length = end - pos;
 830                 *current_ev = iwe_stream_add_point(info, *current_ev,
 831                                                    end_buf, &iwe, pos);
 832         }
 833 }
 834
 835 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 836 {
 837         unsigned long end = jiffies;
 838
 839         if (end >= start)
 840                 return jiffies_to_msecs(end - start);
 841
 842         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 843 }
 844
 845 static char *
 846 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 847               struct cfg80211_internal_bss *bss, char *current_ev,
 848               char *end_buf)
 849 {
 850         struct iw_event iwe;
 851         u8 *buf, *cfg, *p;
 852         u8 *ie = bss->pub.information_elements;
 853         int rem = bss->pub.len_information_elements, i, sig;
 854         bool ismesh = false;
 855
 856         memset(&iwe, 0, sizeof(iwe));
 857         iwe.cmd = SIOCGIWAP;
 858         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 859         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 860         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 861                                           IW_EV_ADDR_LEN);
 862
 863         memset(&iwe, 0, sizeof(iwe));
 864         iwe.cmd = SIOCGIWFREQ;
 865         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 866         iwe.u.freq.e = 0;
 867         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 868                                           IW_EV_FREQ_LEN);
 869
 870         memset(&iwe, 0, sizeof(iwe));
 871         iwe.cmd = SIOCGIWFREQ;
 872         iwe.u.freq.m = bss->pub.channel->center_freq;
 873         iwe.u.freq.e = 6;
 874         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 875                                           IW_EV_FREQ_LEN);
 876
 877         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 878                 memset(&iwe, 0, sizeof(iwe));
 879                 iwe.cmd = IWEVQUAL;
 880                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 881                                      IW_QUAL_NOISE_INVALID |
 882                                      IW_QUAL_QUAL_UPDATED;
 883                 switch (wiphy->signal_type) {
 884                 case CFG80211_SIGNAL_TYPE_MBM:
 885                         sig = bss->pub.signal / 100;
 886                         iwe.u.qual.level = sig;
 887                         iwe.u.qual.updated |= IW_QUAL_DBM;
 888                         if (sig < -110)         /* rather bad */
 889                                 sig = -110;
 890                         else if (sig > -40)     /* perfect */
 891                                 sig = -40;
 892                         /* will give a range of 0 .. 70 */
 893                         iwe.u.qual.qual = sig + 110;
 894                         break;
 895                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 896                         iwe.u.qual.level = bss->pub.signal;
 897                         /* will give range 0 .. 100 */
 898                         iwe.u.qual.qual = bss->pub.signal;
 899                         break;
 900                 default:
 901                         /* not reached */
 902                         break;
 903                 }
 904                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 905                                                   &iwe, IW_EV_QUAL_LEN);
 906         }
 907
 908         memset(&iwe, 0, sizeof(iwe));
 909         iwe.cmd = SIOCGIWENCODE;
 910         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 911                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 912         else
 913                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 914         iwe.u.data.length = 0;
 915         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 916                                           &iwe, "");
 917
 918         while (rem >= 2) {
 919                 /* invalid data */
 920                 if (ie[1] > rem - 2)
 921                         break;
 922
 923                 switch (ie[0]) {
 924                 case WLAN_EID_SSID:
 925                         memset(&iwe, 0, sizeof(iwe));
 926                         iwe.cmd = SIOCGIWESSID;
 927                         iwe.u.data.length = ie[1];
 928                         iwe.u.data.flags = 1;
 929                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 930                                                           &iwe, ie + 2);
 931                         break;
 932                 case WLAN_EID_MESH_ID:
 933                         memset(&iwe, 0, sizeof(iwe));
 934                         iwe.cmd = SIOCGIWESSID;
 935                         iwe.u.data.length = ie[1];
 936                         iwe.u.data.flags = 1;
 937                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 938                                                           &iwe, ie + 2);
 939                         break;
 940                 case WLAN_EID_MESH_CONFIG:
 941                         ismesh = true;
 942                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 943                                 break;
 944                         buf = kmalloc(50, GFP_ATOMIC);
 945                         if (!buf)
 946                                 break;
 947                         cfg = ie + 2;
 948                         memset(&iwe, 0, sizeof(iwe));
 949                         iwe.cmd = IWEVCUSTOM;
 950                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
 951                                 "0x%02X", cfg[0]);
 952                         iwe.u.data.length = strlen(buf);
 953                         current_ev = iwe_stream_add_point(info, current_ev,
 954                                                           end_buf,
 955                                                           &iwe, buf);
 956                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
 957                                 cfg[1]);
 958                         iwe.u.data.length = strlen(buf);
 959                         current_ev = iwe_stream_add_point(info, current_ev,
 960                                                           end_buf,
 961                                                           &iwe, buf);
 962                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
 963                                 cfg[2]);
 964                         iwe.u.data.length = strlen(buf);
 965                         current_ev = iwe_stream_add_point(info, current_ev,
 966                                                           end_buf,
 967                                                           &iwe, buf);
 968                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
 969                         iwe.u.data.length = strlen(buf);
 970                         current_ev = iwe_stream_add_point(info, current_ev,
 971                                                           end_buf,
 972                                                           &iwe, buf);
 973                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
 974                         iwe.u.data.length = strlen(buf);
 975                         current_ev = iwe_stream_add_point(info, current_ev,
 976                                                           end_buf,
 977                                                           &iwe, buf);
 978                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
 979                         iwe.u.data.length = strlen(buf);
 980                         current_ev = iwe_stream_add_point(info, current_ev,
 981                                                           end_buf,
 982                                                           &iwe, buf);
 983                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
 984                         iwe.u.data.length = strlen(buf);
 985                         current_ev = iwe_stream_add_point(info, current_ev,
 986                                                           end_buf,
 987                                                           &iwe, buf);
 988                         kfree(buf);
 989                         break;
 990                 case WLAN_EID_SUPP_RATES:
 991                 case WLAN_EID_EXT_SUPP_RATES:
 992                         /* display all supported rates in readable format */
 993                         p = current_ev + iwe_stream_lcp_len(info);
 994
 995                         memset(&iwe, 0, sizeof(iwe));
 996                         iwe.cmd = SIOCGIWRATE;
 997                         /* Those two flags are ignored... */
 998                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 999
1000                         for (i = 0; i < ie[1]; i++) {
1001                                 iwe.u.bitrate.value =
1002                                         ((ie[i + 2] & 0x7f) * 500000);
1003                                 p = iwe_stream_add_value(info, current_ev, p,
1004                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1005                         }
1006                         current_ev = p;
1007                         break;
1008                 }
1009                 rem -= ie[1] + 2;
1010                 ie += ie[1] + 2;
1011         }
1012
1013         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1014             ismesh) {
1015                 memset(&iwe, 0, sizeof(iwe));
1016                 iwe.cmd = SIOCGIWMODE;
1017                 if (ismesh)
1018                         iwe.u.mode = IW_MODE_MESH;
1019                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1020                         iwe.u.mode = IW_MODE_MASTER;
1021                 else
1022                         iwe.u.mode = IW_MODE_ADHOC;
1023                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1024                                                   &iwe, IW_EV_UINT_LEN);
1025         }
1026
1027         buf = kmalloc(30, GFP_ATOMIC);
1028         if (buf) {
1029                 memset(&iwe, 0, sizeof(iwe));
1030                 iwe.cmd = IWEVCUSTOM;
1031                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1032                 iwe.u.data.length = strlen(buf);
1033                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1034                                                   &iwe, buf);
1035                 memset(&iwe, 0, sizeof(iwe));
1036                 iwe.cmd = IWEVCUSTOM;
1037                 sprintf(buf, " Last beacon: %ums ago",
1038                         elapsed_jiffies_msecs(bss->ts));
1039                 iwe.u.data.length = strlen(buf);
1040                 current_ev = iwe_stream_add_point(info, current_ev,
1041                                                   end_buf, &iwe, buf);
1042                 kfree(buf);
1043         }
1044
1045         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1046
1047         return current_ev;
1048 }
1049
1050
1051 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1052                                   struct iw_request_info *info,
1053                                   char *buf, size_t len)
1054 {
1055         char *current_ev = buf;
1056         char *end_buf = buf + len;
1057         struct cfg80211_internal_bss *bss;
1058
1059         spin_lock_bh(&dev->bss_lock);
1060         cfg80211_bss_expire(dev);
1061
1062         list_for_each_entry(bss, &dev->bss_list, list) {
1063                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1064                         spin_unlock_bh(&dev->bss_lock);
1065                         return -E2BIG;
1066                 }
1067                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1068                                            current_ev, end_buf);
1069         }
1070         spin_unlock_bh(&dev->bss_lock);
1071         return current_ev - buf;
1072 }
1073
1074
1075 int cfg80211_wext_giwscan(struct net_device *dev,
1076                           struct iw_request_info *info,
1077                           struct iw_point *data, char *extra)
1078 {
1079         struct cfg80211_registered_device *rdev;
1080         int res;
1081
1082         if (!netif_running(dev))
1083                 return -ENETDOWN;
1084
1085         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1086
1087         if (IS_ERR(rdev))
1088                 return PTR_ERR(rdev);
1089
1090         if (rdev->scan_req) {
1091                 res = -EAGAIN;
1092                 goto out;
1093         }
1094
1095         res = ieee80211_scan_results(rdev, info, extra, data->length);
1096         data->length = 0;
1097         if (res >= 0) {
1098                 data->length = res;
1099                 res = 0;
1100         }
1101
1102  out:
1103         cfg80211_unlock_rdev(rdev);
1104         return res;
1105 }
1106 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1107 #endif