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 void __cfg80211_sched_scan_results(struct work_struct *wk)
  97 {
  98         struct cfg80211_registered_device *rdev;
  99
 100         rdev = container_of(wk, struct cfg80211_registered_device,
 101                             sched_scan_results_wk);
 102
 103         cfg80211_lock_rdev(rdev);
 104
 105         /* we don't have sched_scan_req anymore if the scan is stopping */
 106         if (rdev->sched_scan_req)
 107                 nl80211_send_sched_scan_results(rdev,
 108                                                 rdev->sched_scan_req->dev);
 109
 110         cfg80211_unlock_rdev(rdev);
 111 }
 112
 113 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 114 {
 115         /* ignore if we're not scanning */
 116         if (wiphy_to_dev(wiphy)->sched_scan_req)
 117                 queue_work(cfg80211_wq,
 118                            &wiphy_to_dev(wiphy)->sched_scan_results_wk);
 119 }
 120 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 121
 122 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 123 {
 124         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 125
 126         cfg80211_lock_rdev(rdev);
 127         __cfg80211_stop_sched_scan(rdev, true);
 128         cfg80211_unlock_rdev(rdev);
 129 }
 130 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 131
 132 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 133                                bool driver_initiated)
 134 {
 135         int err;
 136         struct net_device *dev;
 137
 138         ASSERT_RDEV_LOCK(rdev);
 139
 140         if (!rdev->sched_scan_req)
 141                 return 0;
 142
 143         dev = rdev->sched_scan_req->dev;
 144
 145         if (!driver_initiated) {
 146                 err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
 147                 if (err)
 148                         return err;
 149         }
 150
 151         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 152
 153         kfree(rdev->sched_scan_req);
 154         rdev->sched_scan_req = NULL;
 155
 156         return err;
 157 }
 158
 159 static void bss_release(struct kref *ref)
 160 {
 161         struct cfg80211_internal_bss *bss;
 162
 163         bss = container_of(ref, struct cfg80211_internal_bss, ref);
 164         if (bss->pub.free_priv)
 165                 bss->pub.free_priv(&bss->pub);
 166
 167         if (bss->beacon_ies_allocated)
 168                 kfree(bss->pub.beacon_ies);
 169         if (bss->proberesp_ies_allocated)
 170                 kfree(bss->pub.proberesp_ies);
 171
 172         BUG_ON(atomic_read(&bss->hold));
 173
 174         kfree(bss);
 175 }
 176
 177 /* must hold dev->bss_lock! */
 178 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 179                       unsigned long age_secs)
 180 {
 181         struct cfg80211_internal_bss *bss;
 182         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 183
 184         list_for_each_entry(bss, &dev->bss_list, list) {
 185                 bss->ts -= age_jiffies;
 186         }
 187 }
 188
 189 /* must hold dev->bss_lock! */
 190 static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
 191                                   struct cfg80211_internal_bss *bss)
 192 {
 193         list_del_init(&bss->list);
 194         rb_erase(&bss->rbn, &dev->bss_tree);
 195         kref_put(&bss->ref, bss_release);
 196 }
 197
 198 /* must hold dev->bss_lock! */
 199 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 200 {
 201         struct cfg80211_internal_bss *bss, *tmp;
 202         bool expired = false;
 203
 204         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 205                 if (atomic_read(&bss->hold))
 206                         continue;
 207                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 208                         continue;
 209                 __cfg80211_unlink_bss(dev, bss);
 210                 expired = true;
 211         }
 212
 213         if (expired)
 214                 dev->bss_generation++;
 215 }
 216
 217 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 218 {
 219         while (len > 2 && ies[0] != eid) {
 220                 len -= ies[1] + 2;
 221                 ies += ies[1] + 2;
 222         }
 223         if (len < 2)
 224                 return NULL;
 225         if (len < 2 + ies[1])
 226                 return NULL;
 227         return ies;
 228 }
 229 EXPORT_SYMBOL(cfg80211_find_ie);
 230
 231 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 232 {
 233         const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
 234         const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
 235         int r;
 236
 237         if (!ie1 && !ie2)
 238                 return 0;
 239         if (!ie1 || !ie2)
 240                 return -1;
 241
 242         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 243         if (r == 0 && ie1[1] != ie2[1])
 244                 return ie2[1] - ie1[1];
 245         return r;
 246 }
 247
 248 static bool is_bss(struct cfg80211_bss *a,
 249                    const u8 *bssid,
 250                    const u8 *ssid, size_t ssid_len)
 251 {
 252         const u8 *ssidie;
 253
 254         if (bssid && compare_ether_addr(a->bssid, bssid))
 255                 return false;
 256
 257         if (!ssid)
 258                 return true;
 259
 260         ssidie = cfg80211_find_ie(WLAN_EID_SSID,
 261                                   a->information_elements,
 262                                   a->len_information_elements);
 263         if (!ssidie)
 264                 return false;
 265         if (ssidie[1] != ssid_len)
 266                 return false;
 267         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 268 }
 269
 270 static bool is_mesh(struct cfg80211_bss *a,
 271                     const u8 *meshid, size_t meshidlen,
 272                     const u8 *meshcfg)
 273 {
 274         const u8 *ie;
 275
 276         if (!WLAN_CAPABILITY_IS_MBSS(a->capability))
 277                 return false;
 278
 279         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 280                               a->information_elements,
 281                               a->len_information_elements);
 282         if (!ie)
 283                 return false;
 284         if (ie[1] != meshidlen)
 285                 return false;
 286         if (memcmp(ie + 2, meshid, meshidlen))
 287                 return false;
 288
 289         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 290                               a->information_elements,
 291                               a->len_information_elements);
 292         if (!ie)
 293                 return false;
 294         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 295                 return false;
 296
 297         /*
 298          * Ignore mesh capability (last two bytes of the IE) when
 299          * comparing since that may differ between stations taking
 300          * part in the same mesh.
 301          */
 302         return memcmp(ie + 2, meshcfg,
 303             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
 304 }
 305
 306 static int cmp_bss(struct cfg80211_bss *a,
 307                    struct cfg80211_bss *b)
 308 {
 309         int r;
 310
 311         if (a->channel != b->channel)
 312                 return b->channel->center_freq - a->channel->center_freq;
 313
 314         if (WLAN_CAPABILITY_IS_MBSS(a->capability | b->capability)) {
 315                 r = cmp_ies(WLAN_EID_MESH_ID,
 316                             a->information_elements,
 317                             a->len_information_elements,
 318                             b->information_elements,
 319                             b->len_information_elements);
 320                 if (r)
 321                         return r;
 322                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 323                                a->information_elements,
 324                                a->len_information_elements,
 325                                b->information_elements,
 326                                b->len_information_elements);
 327         }
 328
 329         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 330         if (r)
 331                 return r;
 332
 333         return cmp_ies(WLAN_EID_SSID,
 334                        a->information_elements,
 335                        a->len_information_elements,
 336                        b->information_elements,
 337                        b->len_information_elements);
 338 }
 339
 340 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 341                                       struct ieee80211_channel *channel,
 342                                       const u8 *bssid,
 343                                       const u8 *ssid, size_t ssid_len,
 344                                       u16 capa_mask, u16 capa_val)
 345 {
 346         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 347         struct cfg80211_internal_bss *bss, *res = NULL;
 348         unsigned long now = jiffies;
 349
 350         spin_lock_bh(&dev->bss_lock);
 351
 352         list_for_each_entry(bss, &dev->bss_list, list) {
 353                 if ((bss->pub.capability & capa_mask) != capa_val)
 354                         continue;
 355                 if (channel && bss->pub.channel != channel)
 356                         continue;
 357                 /* Don't get expired BSS structs */
 358                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 359                     !atomic_read(&bss->hold))
 360                         continue;
 361                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 362                         res = bss;
 363                         kref_get(&res->ref);
 364                         break;
 365                 }
 366         }
 367
 368         spin_unlock_bh(&dev->bss_lock);
 369         if (!res)
 370                 return NULL;
 371         return &res->pub;
 372 }
 373 EXPORT_SYMBOL(cfg80211_get_bss);
 374
 375 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 376                                        struct ieee80211_channel *channel,
 377                                        const u8 *meshid, size_t meshidlen,
 378                                        const u8 *meshcfg)
 379 {
 380         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 381         struct cfg80211_internal_bss *bss, *res = NULL;
 382
 383         spin_lock_bh(&dev->bss_lock);
 384
 385         list_for_each_entry(bss, &dev->bss_list, list) {
 386                 if (channel && bss->pub.channel != channel)
 387                         continue;
 388                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 389                         res = bss;
 390                         kref_get(&res->ref);
 391                         break;
 392                 }
 393         }
 394
 395         spin_unlock_bh(&dev->bss_lock);
 396         if (!res)
 397                 return NULL;
 398         return &res->pub;
 399 }
 400 EXPORT_SYMBOL(cfg80211_get_mesh);
 401
 402
 403 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 404                           struct cfg80211_internal_bss *bss)
 405 {
 406         struct rb_node **p = &dev->bss_tree.rb_node;
 407         struct rb_node *parent = NULL;
 408         struct cfg80211_internal_bss *tbss;
 409         int cmp;
 410
 411         while (*p) {
 412                 parent = *p;
 413                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 414
 415                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 416
 417                 if (WARN_ON(!cmp)) {
 418                         /* will sort of leak this BSS */
 419                         return;
 420                 }
 421
 422                 if (cmp < 0)
 423                         p = &(*p)->rb_left;
 424                 else
 425                         p = &(*p)->rb_right;
 426         }
 427
 428         rb_link_node(&bss->rbn, parent, p);
 429         rb_insert_color(&bss->rbn, &dev->bss_tree);
 430 }
 431
 432 static struct cfg80211_internal_bss *
 433 rb_find_bss(struct cfg80211_registered_device *dev,
 434             struct cfg80211_internal_bss *res)
 435 {
 436         struct rb_node *n = dev->bss_tree.rb_node;
 437         struct cfg80211_internal_bss *bss;
 438         int r;
 439
 440         while (n) {
 441                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 442                 r = cmp_bss(&res->pub, &bss->pub);
 443
 444                 if (r == 0)
 445                         return bss;
 446                 else if (r < 0)
 447                         n = n->rb_left;
 448                 else
 449                         n = n->rb_right;
 450         }
 451
 452         return NULL;
 453 }
 454
 455 static struct cfg80211_internal_bss *
 456 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 457                     struct cfg80211_internal_bss *res)
 458 {
 459         struct cfg80211_internal_bss *found = NULL;
 460         const u8 *meshid, *meshcfg;
 461
 462         /*
 463          * The reference to "res" is donated to this function.
 464          */
 465
 466         if (WARN_ON(!res->pub.channel)) {
 467                 kref_put(&res->ref, bss_release);
 468                 return NULL;
 469         }
 470
 471         res->ts = jiffies;
 472
 473         if (WLAN_CAPABILITY_IS_MBSS(res->pub.capability)) {
 474                 /* must be mesh, verify */
 475                 meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
 476                                           res->pub.information_elements,
 477                                           res->pub.len_information_elements);
 478                 meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 479                                            res->pub.information_elements,
 480                                            res->pub.len_information_elements);
 481                 if (!meshid || !meshcfg ||
 482                     meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
 483                         /* bogus mesh */
 484                         kref_put(&res->ref, bss_release);
 485                         return NULL;
 486                 }
 487         }
 488
 489         spin_lock_bh(&dev->bss_lock);
 490
 491         found = rb_find_bss(dev, res);
 492
 493         if (found) {
 494                 found->pub.beacon_interval = res->pub.beacon_interval;
 495                 found->pub.tsf = res->pub.tsf;
 496                 found->pub.signal = res->pub.signal;
 497                 found->pub.capability = res->pub.capability;
 498                 found->ts = res->ts;
 499
 500                 /* Update IEs */
 501                 if (res->pub.proberesp_ies) {
 502                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 503                         size_t ielen = res->pub.len_proberesp_ies;
 504
 505                         if (found->pub.proberesp_ies &&
 506                             !found->proberesp_ies_allocated &&
 507                             ksize(found) >= used + ielen) {
 508                                 memcpy(found->pub.proberesp_ies,
 509                                        res->pub.proberesp_ies, ielen);
 510                                 found->pub.len_proberesp_ies = ielen;
 511                         } else {
 512                                 u8 *ies = found->pub.proberesp_ies;
 513
 514                                 if (found->proberesp_ies_allocated)
 515                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 516                                 else
 517                                         ies = kmalloc(ielen, GFP_ATOMIC);
 518
 519                                 if (ies) {
 520                                         memcpy(ies, res->pub.proberesp_ies,
 521                                                ielen);
 522                                         found->proberesp_ies_allocated = true;
 523                                         found->pub.proberesp_ies = ies;
 524                                         found->pub.len_proberesp_ies = ielen;
 525                                 }
 526                         }
 527
 528                         /* Override possible earlier Beacon frame IEs */
 529                         found->pub.information_elements =
 530                                 found->pub.proberesp_ies;
 531                         found->pub.len_information_elements =
 532                                 found->pub.len_proberesp_ies;
 533                 }
 534                 if (res->pub.beacon_ies) {
 535                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 536                         size_t ielen = res->pub.len_beacon_ies;
 537                         bool information_elements_is_beacon_ies =
 538                                 (found->pub.information_elements ==
 539                                  found->pub.beacon_ies);
 540
 541                         if (found->pub.beacon_ies &&
 542                             !found->beacon_ies_allocated &&
 543                             ksize(found) >= used + ielen) {
 544                                 memcpy(found->pub.beacon_ies,
 545                                        res->pub.beacon_ies, ielen);
 546                                 found->pub.len_beacon_ies = ielen;
 547                         } else {
 548                                 u8 *ies = found->pub.beacon_ies;
 549
 550                                 if (found->beacon_ies_allocated)
 551                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 552                                 else
 553                                         ies = kmalloc(ielen, GFP_ATOMIC);
 554
 555                                 if (ies) {
 556                                         memcpy(ies, res->pub.beacon_ies,
 557                                                ielen);
 558                                         found->beacon_ies_allocated = true;
 559                                         found->pub.beacon_ies = ies;
 560                                         found->pub.len_beacon_ies = ielen;
 561                                 }
 562                         }
 563
 564                         /* Override IEs if they were from a beacon before */
 565                         if (information_elements_is_beacon_ies) {
 566                                 found->pub.information_elements =
 567                                         found->pub.beacon_ies;
 568                                 found->pub.len_information_elements =
 569                                         found->pub.len_beacon_ies;
 570                         }
 571                 }
 572
 573                 kref_put(&res->ref, bss_release);
 574         } else {
 575                 /* this "consumes" the reference */
 576                 list_add_tail(&res->list, &dev->bss_list);
 577                 rb_insert_bss(dev, res);
 578                 found = res;
 579         }
 580
 581         dev->bss_generation++;
 582         spin_unlock_bh(&dev->bss_lock);
 583
 584         kref_get(&found->ref);
 585         return found;
 586 }
 587
 588 struct cfg80211_bss*
 589 cfg80211_inform_bss(struct wiphy *wiphy,
 590                     struct ieee80211_channel *channel,
 591                     const u8 *bssid,
 592                     u64 timestamp, u16 capability, u16 beacon_interval,
 593                     const u8 *ie, size_t ielen,
 594                     s32 signal, gfp_t gfp)
 595 {
 596         struct cfg80211_internal_bss *res;
 597         size_t privsz;
 598
 599         if (WARN_ON(!wiphy))
 600                 return NULL;
 601
 602         privsz = wiphy->bss_priv_size;
 603
 604         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 605                         (signal < 0 || signal > 100)))
 606                 return NULL;
 607
 608         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 609         if (!res)
 610                 return NULL;
 611
 612         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 613         res->pub.channel = channel;
 614         res->pub.signal = signal;
 615         res->pub.tsf = timestamp;
 616         res->pub.beacon_interval = beacon_interval;
 617         res->pub.capability = capability;
 618         /*
 619          * Since we do not know here whether the IEs are from a Beacon or Probe
 620          * Response frame, we need to pick one of the options and only use it
 621          * with the driver that does not provide the full Beacon/Probe Response
 622          * frame. Use Beacon frame pointer to avoid indicating that this should
 623          * override the information_elements pointer should we have received an
 624          * earlier indication of Probe Response data.
 625          *
 626          * The initial buffer for the IEs is allocated with the BSS entry and
 627          * is located after the private area.
 628          */
 629         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
 630         memcpy(res->pub.beacon_ies, ie, ielen);
 631         res->pub.len_beacon_ies = ielen;
 632         res->pub.information_elements = res->pub.beacon_ies;
 633         res->pub.len_information_elements = res->pub.len_beacon_ies;
 634
 635         kref_init(&res->ref);
 636
 637         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 638         if (!res)
 639                 return NULL;
 640
 641         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 642                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 643
 644         /* cfg80211_bss_update gives us a referenced result */
 645         return &res->pub;
 646 }
 647 EXPORT_SYMBOL(cfg80211_inform_bss);
 648
 649 struct cfg80211_bss *
 650 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 651                           struct ieee80211_channel *channel,
 652                           struct ieee80211_mgmt *mgmt, size_t len,
 653                           s32 signal, gfp_t gfp)
 654 {
 655         struct cfg80211_internal_bss *res;
 656         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 657                                       u.probe_resp.variable);
 658         size_t privsz;
 659
 660         if (WARN_ON(!mgmt))
 661                 return NULL;
 662
 663         if (WARN_ON(!wiphy))
 664                 return NULL;
 665
 666         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 667                     (signal < 0 || signal > 100)))
 668                 return NULL;
 669
 670         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 671                 return NULL;
 672
 673         privsz = wiphy->bss_priv_size;
 674
 675         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 676         if (!res)
 677                 return NULL;
 678
 679         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 680         res->pub.channel = channel;
 681         res->pub.signal = signal;
 682         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 683         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 684         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 685         /*
 686          * The initial buffer for the IEs is allocated with the BSS entry and
 687          * is located after the private area.
 688          */
 689         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 690                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
 691                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
 692                        ielen);
 693                 res->pub.len_proberesp_ies = ielen;
 694                 res->pub.information_elements = res->pub.proberesp_ies;
 695                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
 696         } else {
 697                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
 698                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
 699                 res->pub.len_beacon_ies = ielen;
 700                 res->pub.information_elements = res->pub.beacon_ies;
 701                 res->pub.len_information_elements = res->pub.len_beacon_ies;
 702         }
 703
 704         kref_init(&res->ref);
 705
 706         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 707         if (!res)
 708                 return NULL;
 709
 710         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 711                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 712
 713         /* cfg80211_bss_update gives us a referenced result */
 714         return &res->pub;
 715 }
 716 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 717
 718 void cfg80211_put_bss(struct cfg80211_bss *pub)
 719 {
 720         struct cfg80211_internal_bss *bss;
 721
 722         if (!pub)
 723                 return;
 724
 725         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 726         kref_put(&bss->ref, bss_release);
 727 }
 728 EXPORT_SYMBOL(cfg80211_put_bss);
 729
 730 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 731 {
 732         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 733         struct cfg80211_internal_bss *bss;
 734
 735         if (WARN_ON(!pub))
 736                 return;
 737
 738         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 739
 740         spin_lock_bh(&dev->bss_lock);
 741         if (!list_empty(&bss->list)) {
 742                 __cfg80211_unlink_bss(dev, bss);
 743                 dev->bss_generation++;
 744         }
 745         spin_unlock_bh(&dev->bss_lock);
 746 }
 747 EXPORT_SYMBOL(cfg80211_unlink_bss);
 748
 749 #ifdef CONFIG_CFG80211_WEXT
 750 int cfg80211_wext_siwscan(struct net_device *dev,
 751                           struct iw_request_info *info,
 752                           union iwreq_data *wrqu, char *extra)
 753 {
 754         struct cfg80211_registered_device *rdev;
 755         struct wiphy *wiphy;
 756         struct iw_scan_req *wreq = NULL;
 757         struct cfg80211_scan_request *creq = NULL;
 758         int i, err, n_channels = 0;
 759         enum ieee80211_band band;
 760
 761         if (!netif_running(dev))
 762                 return -ENETDOWN;
 763
 764         if (wrqu->data.length == sizeof(struct iw_scan_req))
 765                 wreq = (struct iw_scan_req *)extra;
 766
 767         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 768
 769         if (IS_ERR(rdev))
 770                 return PTR_ERR(rdev);
 771
 772         if (rdev->scan_req) {
 773                 err = -EBUSY;
 774                 goto out;
 775         }
 776
 777         wiphy = &rdev->wiphy;
 778
 779         /* Determine number of channels, needed to allocate creq */
 780         if (wreq && wreq->num_channels)
 781                 n_channels = wreq->num_channels;
 782         else {
 783                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 784                         if (wiphy->bands[band])
 785                                 n_channels += wiphy->bands[band]->n_channels;
 786         }
 787
 788         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 789                        n_channels * sizeof(void *),
 790                        GFP_ATOMIC);
 791         if (!creq) {
 792                 err = -ENOMEM;
 793                 goto out;
 794         }
 795
 796         creq->wiphy = wiphy;
 797         creq->dev = dev;
 798         /* SSIDs come after channels */
 799         creq->ssids = (void *)&creq->channels[n_channels];
 800         creq->n_channels = n_channels;
 801         creq->n_ssids = 1;
 802
 803         /* translate "Scan on frequencies" request */
 804         i = 0;
 805         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 806                 int j;
 807
 808                 if (!wiphy->bands[band])
 809                         continue;
 810
 811                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 812                         /* ignore disabled channels */
 813                         if (wiphy->bands[band]->channels[j].flags &
 814                                                 IEEE80211_CHAN_DISABLED)
 815                                 continue;
 816
 817                         /* If we have a wireless request structure and the
 818                          * wireless request specifies frequencies, then search
 819                          * for the matching hardware channel.
 820                          */
 821                         if (wreq && wreq->num_channels) {
 822                                 int k;
 823                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 824                                 for (k = 0; k < wreq->num_channels; k++) {
 825                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 826                                         if (wext_freq == wiphy_freq)
 827                                                 goto wext_freq_found;
 828                                 }
 829                                 goto wext_freq_not_found;
 830                         }
 831
 832                 wext_freq_found:
 833                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 834                         i++;
 835                 wext_freq_not_found: ;
 836                 }
 837         }
 838         /* No channels found? */
 839         if (!i) {
 840                 err = -EINVAL;
 841                 goto out;
 842         }
 843
 844         /* Set real number of channels specified in creq->channels[] */
 845         creq->n_channels = i;
 846
 847         /* translate "Scan for SSID" request */
 848         if (wreq) {
 849                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 850                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
 851                                 err = -EINVAL;
 852                                 goto out;
 853                         }
 854                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 855                         creq->ssids[0].ssid_len = wreq->essid_len;
 856                 }
 857                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 858                         creq->n_ssids = 0;
 859         }
 860
 861         rdev->scan_req = creq;
 862         err = rdev->ops->scan(wiphy, dev, creq);
 863         if (err) {
 864                 rdev->scan_req = NULL;
 865                 /* creq will be freed below */
 866         } else {
 867                 nl80211_send_scan_start(rdev, dev);
 868                 /* creq now owned by driver */
 869                 creq = NULL;
 870                 dev_hold(dev);
 871         }
 872  out:
 873         kfree(creq);
 874         cfg80211_unlock_rdev(rdev);
 875         return err;
 876 }
 877 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 878
 879 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 880                                    struct cfg80211_bss *bss,
 881                                    char **current_ev, char *end_buf)
 882 {
 883         u8 *pos, *end, *next;
 884         struct iw_event iwe;
 885
 886         if (!bss->information_elements ||
 887             !bss->len_information_elements)
 888                 return;
 889
 890         /*
 891          * If needed, fragment the IEs buffer (at IE boundaries) into short
 892          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 893          */
 894         pos = bss->information_elements;
 895         end = pos + bss->len_information_elements;
 896
 897         while (end - pos > IW_GENERIC_IE_MAX) {
 898                 next = pos + 2 + pos[1];
 899                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 900                         next = next + 2 + next[1];
 901
 902                 memset(&iwe, 0, sizeof(iwe));
 903                 iwe.cmd = IWEVGENIE;
 904                 iwe.u.data.length = next - pos;
 905                 *current_ev = iwe_stream_add_point(info, *current_ev,
 906                                                    end_buf, &iwe, pos);
 907
 908                 pos = next;
 909         }
 910
 911         if (end > pos) {
 912                 memset(&iwe, 0, sizeof(iwe));
 913                 iwe.cmd = IWEVGENIE;
 914                 iwe.u.data.length = end - pos;
 915                 *current_ev = iwe_stream_add_point(info, *current_ev,
 916                                                    end_buf, &iwe, pos);
 917         }
 918 }
 919
 920 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 921 {
 922         unsigned long end = jiffies;
 923
 924         if (end >= start)
 925                 return jiffies_to_msecs(end - start);
 926
 927         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 928 }
 929
 930 static char *
 931 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 932               struct cfg80211_internal_bss *bss, char *current_ev,
 933               char *end_buf)
 934 {
 935         struct iw_event iwe;
 936         u8 *buf, *cfg, *p;
 937         u8 *ie = bss->pub.information_elements;
 938         int rem = bss->pub.len_information_elements, i, sig;
 939         bool ismesh = false;
 940
 941         memset(&iwe, 0, sizeof(iwe));
 942         iwe.cmd = SIOCGIWAP;
 943         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 944         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 945         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 946                                           IW_EV_ADDR_LEN);
 947
 948         memset(&iwe, 0, sizeof(iwe));
 949         iwe.cmd = SIOCGIWFREQ;
 950         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 951         iwe.u.freq.e = 0;
 952         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 953                                           IW_EV_FREQ_LEN);
 954
 955         memset(&iwe, 0, sizeof(iwe));
 956         iwe.cmd = SIOCGIWFREQ;
 957         iwe.u.freq.m = bss->pub.channel->center_freq;
 958         iwe.u.freq.e = 6;
 959         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 960                                           IW_EV_FREQ_LEN);
 961
 962         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 963                 memset(&iwe, 0, sizeof(iwe));
 964                 iwe.cmd = IWEVQUAL;
 965                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 966                                      IW_QUAL_NOISE_INVALID |
 967                                      IW_QUAL_QUAL_UPDATED;
 968                 switch (wiphy->signal_type) {
 969                 case CFG80211_SIGNAL_TYPE_MBM:
 970                         sig = bss->pub.signal / 100;
 971                         iwe.u.qual.level = sig;
 972                         iwe.u.qual.updated |= IW_QUAL_DBM;
 973                         if (sig < -110)         /* rather bad */
 974                                 sig = -110;
 975                         else if (sig > -40)     /* perfect */
 976                                 sig = -40;
 977                         /* will give a range of 0 .. 70 */
 978                         iwe.u.qual.qual = sig + 110;
 979                         break;
 980                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 981                         iwe.u.qual.level = bss->pub.signal;
 982                         /* will give range 0 .. 100 */
 983                         iwe.u.qual.qual = bss->pub.signal;
 984                         break;
 985                 default:
 986                         /* not reached */
 987                         break;
 988                 }
 989                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 990                                                   &iwe, IW_EV_QUAL_LEN);
 991         }
 992
 993         memset(&iwe, 0, sizeof(iwe));
 994         iwe.cmd = SIOCGIWENCODE;
 995         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 996                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 997         else
 998                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 999         iwe.u.data.length = 0;
1000         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1001                                           &iwe, "");
1002
1003         while (rem >= 2) {
1004                 /* invalid data */
1005                 if (ie[1] > rem - 2)
1006                         break;
1007
1008                 switch (ie[0]) {
1009                 case WLAN_EID_SSID:
1010                         memset(&iwe, 0, sizeof(iwe));
1011                         iwe.cmd = SIOCGIWESSID;
1012                         iwe.u.data.length = ie[1];
1013                         iwe.u.data.flags = 1;
1014                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1015                                                           &iwe, ie + 2);
1016                         break;
1017                 case WLAN_EID_MESH_ID:
1018                         memset(&iwe, 0, sizeof(iwe));
1019                         iwe.cmd = SIOCGIWESSID;
1020                         iwe.u.data.length = ie[1];
1021                         iwe.u.data.flags = 1;
1022                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1023                                                           &iwe, ie + 2);
1024                         break;
1025                 case WLAN_EID_MESH_CONFIG:
1026                         ismesh = true;
1027                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1028                                 break;
1029                         buf = kmalloc(50, GFP_ATOMIC);
1030                         if (!buf)
1031                                 break;
1032                         cfg = ie + 2;
1033                         memset(&iwe, 0, sizeof(iwe));
1034                         iwe.cmd = IWEVCUSTOM;
1035                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1036                                 "0x%02X", cfg[0]);
1037                         iwe.u.data.length = strlen(buf);
1038                         current_ev = iwe_stream_add_point(info, current_ev,
1039                                                           end_buf,
1040                                                           &iwe, buf);
1041                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1042                                 cfg[1]);
1043                         iwe.u.data.length = strlen(buf);
1044                         current_ev = iwe_stream_add_point(info, current_ev,
1045                                                           end_buf,
1046                                                           &iwe, buf);
1047                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1048                                 cfg[2]);
1049                         iwe.u.data.length = strlen(buf);
1050                         current_ev = iwe_stream_add_point(info, current_ev,
1051                                                           end_buf,
1052                                                           &iwe, buf);
1053                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1054                         iwe.u.data.length = strlen(buf);
1055                         current_ev = iwe_stream_add_point(info, current_ev,
1056                                                           end_buf,
1057                                                           &iwe, buf);
1058                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1059                         iwe.u.data.length = strlen(buf);
1060                         current_ev = iwe_stream_add_point(info, current_ev,
1061                                                           end_buf,
1062                                                           &iwe, buf);
1063                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1064                         iwe.u.data.length = strlen(buf);
1065                         current_ev = iwe_stream_add_point(info, current_ev,
1066                                                           end_buf,
1067                                                           &iwe, buf);
1068                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1069                         iwe.u.data.length = strlen(buf);
1070                         current_ev = iwe_stream_add_point(info, current_ev,
1071                                                           end_buf,
1072                                                           &iwe, buf);
1073                         kfree(buf);
1074                         break;
1075                 case WLAN_EID_SUPP_RATES:
1076                 case WLAN_EID_EXT_SUPP_RATES:
1077                         /* display all supported rates in readable format */
1078                         p = current_ev + iwe_stream_lcp_len(info);
1079
1080                         memset(&iwe, 0, sizeof(iwe));
1081                         iwe.cmd = SIOCGIWRATE;
1082                         /* Those two flags are ignored... */
1083                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1084
1085                         for (i = 0; i < ie[1]; i++) {
1086                                 iwe.u.bitrate.value =
1087                                         ((ie[i + 2] & 0x7f) * 500000);
1088                                 p = iwe_stream_add_value(info, current_ev, p,
1089                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1090                         }
1091                         current_ev = p;
1092                         break;
1093                 }
1094                 rem -= ie[1] + 2;
1095                 ie += ie[1] + 2;
1096         }
1097
1098         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1099             ismesh) {
1100                 memset(&iwe, 0, sizeof(iwe));
1101                 iwe.cmd = SIOCGIWMODE;
1102                 if (ismesh)
1103                         iwe.u.mode = IW_MODE_MESH;
1104                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1105                         iwe.u.mode = IW_MODE_MASTER;
1106                 else
1107                         iwe.u.mode = IW_MODE_ADHOC;
1108                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1109                                                   &iwe, IW_EV_UINT_LEN);
1110         }
1111
1112         buf = kmalloc(30, GFP_ATOMIC);
1113         if (buf) {
1114                 memset(&iwe, 0, sizeof(iwe));
1115                 iwe.cmd = IWEVCUSTOM;
1116                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1117                 iwe.u.data.length = strlen(buf);
1118                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1119                                                   &iwe, buf);
1120                 memset(&iwe, 0, sizeof(iwe));
1121                 iwe.cmd = IWEVCUSTOM;
1122                 sprintf(buf, " Last beacon: %ums ago",
1123                         elapsed_jiffies_msecs(bss->ts));
1124                 iwe.u.data.length = strlen(buf);
1125                 current_ev = iwe_stream_add_point(info, current_ev,
1126                                                   end_buf, &iwe, buf);
1127                 kfree(buf);
1128         }
1129
1130         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1131
1132         return current_ev;
1133 }
1134
1135
1136 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1137                                   struct iw_request_info *info,
1138                                   char *buf, size_t len)
1139 {
1140         char *current_ev = buf;
1141         char *end_buf = buf + len;
1142         struct cfg80211_internal_bss *bss;
1143
1144         spin_lock_bh(&dev->bss_lock);
1145         cfg80211_bss_expire(dev);
1146
1147         list_for_each_entry(bss, &dev->bss_list, list) {
1148                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1149                         spin_unlock_bh(&dev->bss_lock);
1150                         return -E2BIG;
1151                 }
1152                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1153                                            current_ev, end_buf);
1154         }
1155         spin_unlock_bh(&dev->bss_lock);
1156         return current_ev - buf;
1157 }
1158
1159
1160 int cfg80211_wext_giwscan(struct net_device *dev,
1161                           struct iw_request_info *info,
1162                           struct iw_point *data, char *extra)
1163 {
1164         struct cfg80211_registered_device *rdev;
1165         int res;
1166
1167         if (!netif_running(dev))
1168                 return -ENETDOWN;
1169
1170         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1171
1172         if (IS_ERR(rdev))
1173                 return PTR_ERR(rdev);
1174
1175         if (rdev->scan_req) {
1176                 res = -EAGAIN;
1177                 goto out;
1178         }
1179
1180         res = ieee80211_scan_results(rdev, info, extra, data->length);
1181         data->length = 0;
1182         if (res >= 0) {
1183                 data->length = res;
1184                 res = 0;
1185         }
1186
1187  out:
1188         cfg80211_unlock_rdev(rdev);
1189         return res;
1190 }
1191 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1192 #endif