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         mutex_lock(&rdev->sched_scan_mtx);
 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         mutex_unlock(&rdev->sched_scan_mtx);
 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         mutex_lock(&rdev->sched_scan_mtx);
 127         __cfg80211_stop_sched_scan(rdev, true);
 128         mutex_unlock(&rdev->sched_scan_mtx);
 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         struct net_device *dev;
 136
 137         lockdep_assert_held(&rdev->sched_scan_mtx);
 138
 139         if (!rdev->sched_scan_req)
 140                 return -ENOENT;
 141
 142         dev = rdev->sched_scan_req->dev;
 143
 144         if (!driver_initiated) {
 145                 int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
 146                 if (err)
 147                         return err;
 148         }
 149
 150         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 151
 152         kfree(rdev->sched_scan_req);
 153         rdev->sched_scan_req = NULL;
 154
 155         return 0;
 156 }
 157
 158 static void bss_release(struct kref *ref)
 159 {
 160         struct cfg80211_internal_bss *bss;
 161
 162         bss = container_of(ref, struct cfg80211_internal_bss, ref);
 163         if (bss->pub.free_priv)
 164                 bss->pub.free_priv(&bss->pub);
 165
 166         if (bss->beacon_ies_allocated)
 167                 kfree(bss->pub.beacon_ies);
 168         if (bss->proberesp_ies_allocated)
 169                 kfree(bss->pub.proberesp_ies);
 170
 171         BUG_ON(atomic_read(&bss->hold));
 172
 173         kfree(bss);
 174 }
 175
 176 /* must hold dev->bss_lock! */
 177 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 178                       unsigned long age_secs)
 179 {
 180         struct cfg80211_internal_bss *bss;
 181         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 182
 183         list_for_each_entry(bss, &dev->bss_list, list) {
 184                 bss->ts -= age_jiffies;
 185         }
 186 }
 187
 188 /* must hold dev->bss_lock! */
 189 static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
 190                                   struct cfg80211_internal_bss *bss)
 191 {
 192         list_del_init(&bss->list);
 193         rb_erase(&bss->rbn, &dev->bss_tree);
 194         kref_put(&bss->ref, bss_release);
 195 }
 196
 197 /* must hold dev->bss_lock! */
 198 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 199 {
 200         struct cfg80211_internal_bss *bss, *tmp;
 201         bool expired = false;
 202
 203         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 204                 if (atomic_read(&bss->hold))
 205                         continue;
 206                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 207                         continue;
 208                 __cfg80211_unlink_bss(dev, bss);
 209                 expired = true;
 210         }
 211
 212         if (expired)
 213                 dev->bss_generation++;
 214 }
 215
 216 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 217 {
 218         while (len > 2 && ies[0] != eid) {
 219                 len -= ies[1] + 2;
 220                 ies += ies[1] + 2;
 221         }
 222         if (len < 2)
 223                 return NULL;
 224         if (len < 2 + ies[1])
 225                 return NULL;
 226         return ies;
 227 }
 228 EXPORT_SYMBOL(cfg80211_find_ie);
 229
 230 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 231 {
 232         const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
 233         const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
 234         int r;
 235
 236         if (!ie1 && !ie2)
 237                 return 0;
 238         if (!ie1 || !ie2)
 239                 return -1;
 240
 241         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 242         if (r == 0 && ie1[1] != ie2[1])
 243                 return ie2[1] - ie1[1];
 244         return r;
 245 }
 246
 247 static bool is_bss(struct cfg80211_bss *a,
 248                    const u8 *bssid,
 249                    const u8 *ssid, size_t ssid_len)
 250 {
 251         const u8 *ssidie;
 252
 253         if (bssid && compare_ether_addr(a->bssid, bssid))
 254                 return false;
 255
 256         if (!ssid)
 257                 return true;
 258
 259         ssidie = cfg80211_find_ie(WLAN_EID_SSID,
 260                                   a->information_elements,
 261                                   a->len_information_elements);
 262         if (!ssidie)
 263                 return false;
 264         if (ssidie[1] != ssid_len)
 265                 return false;
 266         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 267 }
 268
 269 static bool is_mesh_bss(struct cfg80211_bss *a)
 270 {
 271         const u8 *ie;
 272
 273         if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 274                 return false;
 275
 276         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 277                               a->information_elements,
 278                               a->len_information_elements);
 279         if (!ie)
 280                 return false;
 281
 282         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 283                               a->information_elements,
 284                               a->len_information_elements);
 285         if (!ie)
 286                 return false;
 287
 288         return true;
 289 }
 290
 291 static bool is_mesh(struct cfg80211_bss *a,
 292                     const u8 *meshid, size_t meshidlen,
 293                     const u8 *meshcfg)
 294 {
 295         const u8 *ie;
 296
 297         if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 298                 return false;
 299
 300         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 301                               a->information_elements,
 302                               a->len_information_elements);
 303         if (!ie)
 304                 return false;
 305         if (ie[1] != meshidlen)
 306                 return false;
 307         if (memcmp(ie + 2, meshid, meshidlen))
 308                 return false;
 309
 310         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 311                               a->information_elements,
 312                               a->len_information_elements);
 313         if (!ie)
 314                 return false;
 315         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 316                 return false;
 317
 318         /*
 319          * Ignore mesh capability (last two bytes of the IE) when
 320          * comparing since that may differ between stations taking
 321          * part in the same mesh.
 322          */
 323         return memcmp(ie + 2, meshcfg,
 324             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
 325 }
 326
 327 static int cmp_bss(struct cfg80211_bss *a,
 328                    struct cfg80211_bss *b)
 329 {
 330         int r;
 331
 332         if (a->channel != b->channel)
 333                 return b->channel->center_freq - a->channel->center_freq;
 334
 335         if (is_mesh_bss(a) && is_mesh_bss(b)) {
 336                 r = cmp_ies(WLAN_EID_MESH_ID,
 337                             a->information_elements,
 338                             a->len_information_elements,
 339                             b->information_elements,
 340                             b->len_information_elements);
 341                 if (r)
 342                         return r;
 343                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 344                                a->information_elements,
 345                                a->len_information_elements,
 346                                b->information_elements,
 347                                b->len_information_elements);
 348         }
 349
 350         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 351         if (r)
 352                 return r;
 353
 354         return cmp_ies(WLAN_EID_SSID,
 355                        a->information_elements,
 356                        a->len_information_elements,
 357                        b->information_elements,
 358                        b->len_information_elements);
 359 }
 360
 361 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 362                                       struct ieee80211_channel *channel,
 363                                       const u8 *bssid,
 364                                       const u8 *ssid, size_t ssid_len,
 365                                       u16 capa_mask, u16 capa_val)
 366 {
 367         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 368         struct cfg80211_internal_bss *bss, *res = NULL;
 369         unsigned long now = jiffies;
 370
 371         spin_lock_bh(&dev->bss_lock);
 372
 373         list_for_each_entry(bss, &dev->bss_list, list) {
 374                 if ((bss->pub.capability & capa_mask) != capa_val)
 375                         continue;
 376                 if (channel && bss->pub.channel != channel)
 377                         continue;
 378                 /* Don't get expired BSS structs */
 379                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 380                     !atomic_read(&bss->hold))
 381                         continue;
 382                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 383                         res = bss;
 384                         kref_get(&res->ref);
 385                         break;
 386                 }
 387         }
 388
 389         spin_unlock_bh(&dev->bss_lock);
 390         if (!res)
 391                 return NULL;
 392         return &res->pub;
 393 }
 394 EXPORT_SYMBOL(cfg80211_get_bss);
 395
 396 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 397                                        struct ieee80211_channel *channel,
 398                                        const u8 *meshid, size_t meshidlen,
 399                                        const u8 *meshcfg)
 400 {
 401         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 402         struct cfg80211_internal_bss *bss, *res = NULL;
 403
 404         spin_lock_bh(&dev->bss_lock);
 405
 406         list_for_each_entry(bss, &dev->bss_list, list) {
 407                 if (channel && bss->pub.channel != channel)
 408                         continue;
 409                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 410                         res = bss;
 411                         kref_get(&res->ref);
 412                         break;
 413                 }
 414         }
 415
 416         spin_unlock_bh(&dev->bss_lock);
 417         if (!res)
 418                 return NULL;
 419         return &res->pub;
 420 }
 421 EXPORT_SYMBOL(cfg80211_get_mesh);
 422
 423
 424 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 425                           struct cfg80211_internal_bss *bss)
 426 {
 427         struct rb_node **p = &dev->bss_tree.rb_node;
 428         struct rb_node *parent = NULL;
 429         struct cfg80211_internal_bss *tbss;
 430         int cmp;
 431
 432         while (*p) {
 433                 parent = *p;
 434                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 435
 436                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 437
 438                 if (WARN_ON(!cmp)) {
 439                         /* will sort of leak this BSS */
 440                         return;
 441                 }
 442
 443                 if (cmp < 0)
 444                         p = &(*p)->rb_left;
 445                 else
 446                         p = &(*p)->rb_right;
 447         }
 448
 449         rb_link_node(&bss->rbn, parent, p);
 450         rb_insert_color(&bss->rbn, &dev->bss_tree);
 451 }
 452
 453 static struct cfg80211_internal_bss *
 454 rb_find_bss(struct cfg80211_registered_device *dev,
 455             struct cfg80211_internal_bss *res)
 456 {
 457         struct rb_node *n = dev->bss_tree.rb_node;
 458         struct cfg80211_internal_bss *bss;
 459         int r;
 460
 461         while (n) {
 462                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 463                 r = cmp_bss(&res->pub, &bss->pub);
 464
 465                 if (r == 0)
 466                         return bss;
 467                 else if (r < 0)
 468                         n = n->rb_left;
 469                 else
 470                         n = n->rb_right;
 471         }
 472
 473         return NULL;
 474 }
 475
 476 static struct cfg80211_internal_bss *
 477 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 478                     struct cfg80211_internal_bss *res)
 479 {
 480         struct cfg80211_internal_bss *found = NULL;
 481
 482         /*
 483          * The reference to "res" is donated to this function.
 484          */
 485
 486         if (WARN_ON(!res->pub.channel)) {
 487                 kref_put(&res->ref, bss_release);
 488                 return NULL;
 489         }
 490
 491         res->ts = jiffies;
 492
 493         spin_lock_bh(&dev->bss_lock);
 494
 495         found = rb_find_bss(dev, res);
 496
 497         if (found) {
 498                 found->pub.beacon_interval = res->pub.beacon_interval;
 499                 found->pub.tsf = res->pub.tsf;
 500                 found->pub.signal = res->pub.signal;
 501                 found->pub.capability = res->pub.capability;
 502                 found->ts = res->ts;
 503
 504                 /* Update IEs */
 505                 if (res->pub.proberesp_ies) {
 506                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 507                         size_t ielen = res->pub.len_proberesp_ies;
 508
 509                         if (found->pub.proberesp_ies &&
 510                             !found->proberesp_ies_allocated &&
 511                             ksize(found) >= used + ielen) {
 512                                 memcpy(found->pub.proberesp_ies,
 513                                        res->pub.proberesp_ies, ielen);
 514                                 found->pub.len_proberesp_ies = ielen;
 515                         } else {
 516                                 u8 *ies = found->pub.proberesp_ies;
 517
 518                                 if (found->proberesp_ies_allocated)
 519                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 520                                 else
 521                                         ies = kmalloc(ielen, GFP_ATOMIC);
 522
 523                                 if (ies) {
 524                                         memcpy(ies, res->pub.proberesp_ies,
 525                                                ielen);
 526                                         found->proberesp_ies_allocated = true;
 527                                         found->pub.proberesp_ies = ies;
 528                                         found->pub.len_proberesp_ies = ielen;
 529                                 }
 530                         }
 531
 532                         /* Override possible earlier Beacon frame IEs */
 533                         found->pub.information_elements =
 534                                 found->pub.proberesp_ies;
 535                         found->pub.len_information_elements =
 536                                 found->pub.len_proberesp_ies;
 537                 }
 538                 if (res->pub.beacon_ies) {
 539                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 540                         size_t ielen = res->pub.len_beacon_ies;
 541                         bool information_elements_is_beacon_ies =
 542                                 (found->pub.information_elements ==
 543                                  found->pub.beacon_ies);
 544
 545                         if (found->pub.beacon_ies &&
 546                             !found->beacon_ies_allocated &&
 547                             ksize(found) >= used + ielen) {
 548                                 memcpy(found->pub.beacon_ies,
 549                                        res->pub.beacon_ies, ielen);
 550                                 found->pub.len_beacon_ies = ielen;
 551                         } else {
 552                                 u8 *ies = found->pub.beacon_ies;
 553
 554                                 if (found->beacon_ies_allocated)
 555                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 556                                 else
 557                                         ies = kmalloc(ielen, GFP_ATOMIC);
 558
 559                                 if (ies) {
 560                                         memcpy(ies, res->pub.beacon_ies,
 561                                                ielen);
 562                                         found->beacon_ies_allocated = true;
 563                                         found->pub.beacon_ies = ies;
 564                                         found->pub.len_beacon_ies = ielen;
 565                                 }
 566                         }
 567
 568                         /* Override IEs if they were from a beacon before */
 569                         if (information_elements_is_beacon_ies) {
 570                                 found->pub.information_elements =
 571                                         found->pub.beacon_ies;
 572                                 found->pub.len_information_elements =
 573                                         found->pub.len_beacon_ies;
 574                         }
 575                 }
 576
 577                 kref_put(&res->ref, bss_release);
 578         } else {
 579                 /* this "consumes" the reference */
 580                 list_add_tail(&res->list, &dev->bss_list);
 581                 rb_insert_bss(dev, res);
 582                 found = res;
 583         }
 584
 585         dev->bss_generation++;
 586         spin_unlock_bh(&dev->bss_lock);
 587
 588         kref_get(&found->ref);
 589         return found;
 590 }
 591
 592 struct cfg80211_bss*
 593 cfg80211_inform_bss(struct wiphy *wiphy,
 594                     struct ieee80211_channel *channel,
 595                     const u8 *bssid,
 596                     u64 timestamp, u16 capability, u16 beacon_interval,
 597                     const u8 *ie, size_t ielen,
 598                     s32 signal, gfp_t gfp)
 599 {
 600         struct cfg80211_internal_bss *res;
 601         size_t privsz;
 602
 603         if (WARN_ON(!wiphy))
 604                 return NULL;
 605
 606         privsz = wiphy->bss_priv_size;
 607
 608         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 609                         (signal < 0 || signal > 100)))
 610                 return NULL;
 611
 612         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 613         if (!res)
 614                 return NULL;
 615
 616         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 617         res->pub.channel = channel;
 618         res->pub.signal = signal;
 619         res->pub.tsf = timestamp;
 620         res->pub.beacon_interval = beacon_interval;
 621         res->pub.capability = capability;
 622         /*
 623          * Since we do not know here whether the IEs are from a Beacon or Probe
 624          * Response frame, we need to pick one of the options and only use it
 625          * with the driver that does not provide the full Beacon/Probe Response
 626          * frame. Use Beacon frame pointer to avoid indicating that this should
 627          * override the information_elements pointer should we have received an
 628          * earlier indication of Probe Response data.
 629          *
 630          * The initial buffer for the IEs is allocated with the BSS entry and
 631          * is located after the private area.
 632          */
 633         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
 634         memcpy(res->pub.beacon_ies, ie, ielen);
 635         res->pub.len_beacon_ies = ielen;
 636         res->pub.information_elements = res->pub.beacon_ies;
 637         res->pub.len_information_elements = res->pub.len_beacon_ies;
 638
 639         kref_init(&res->ref);
 640
 641         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 642         if (!res)
 643                 return NULL;
 644
 645         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 646                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 647
 648         /* cfg80211_bss_update gives us a referenced result */
 649         return &res->pub;
 650 }
 651 EXPORT_SYMBOL(cfg80211_inform_bss);
 652
 653 struct cfg80211_bss *
 654 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 655                           struct ieee80211_channel *channel,
 656                           struct ieee80211_mgmt *mgmt, size_t len,
 657                           s32 signal, gfp_t gfp)
 658 {
 659         struct cfg80211_internal_bss *res;
 660         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 661                                       u.probe_resp.variable);
 662         size_t privsz;
 663
 664         if (WARN_ON(!mgmt))
 665                 return NULL;
 666
 667         if (WARN_ON(!wiphy))
 668                 return NULL;
 669
 670         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 671                     (signal < 0 || signal > 100)))
 672                 return NULL;
 673
 674         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 675                 return NULL;
 676
 677         privsz = wiphy->bss_priv_size;
 678
 679         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 680         if (!res)
 681                 return NULL;
 682
 683         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 684         res->pub.channel = channel;
 685         res->pub.signal = signal;
 686         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 687         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 688         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 689         /*
 690          * The initial buffer for the IEs is allocated with the BSS entry and
 691          * is located after the private area.
 692          */
 693         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 694                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
 695                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
 696                        ielen);
 697                 res->pub.len_proberesp_ies = ielen;
 698                 res->pub.information_elements = res->pub.proberesp_ies;
 699                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
 700         } else {
 701                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
 702                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
 703                 res->pub.len_beacon_ies = ielen;
 704                 res->pub.information_elements = res->pub.beacon_ies;
 705                 res->pub.len_information_elements = res->pub.len_beacon_ies;
 706         }
 707
 708         kref_init(&res->ref);
 709
 710         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 711         if (!res)
 712                 return NULL;
 713
 714         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 715                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 716
 717         /* cfg80211_bss_update gives us a referenced result */
 718         return &res->pub;
 719 }
 720 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 721
 722 void cfg80211_put_bss(struct cfg80211_bss *pub)
 723 {
 724         struct cfg80211_internal_bss *bss;
 725
 726         if (!pub)
 727                 return;
 728
 729         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 730         kref_put(&bss->ref, bss_release);
 731 }
 732 EXPORT_SYMBOL(cfg80211_put_bss);
 733
 734 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 735 {
 736         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 737         struct cfg80211_internal_bss *bss;
 738
 739         if (WARN_ON(!pub))
 740                 return;
 741
 742         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 743
 744         spin_lock_bh(&dev->bss_lock);
 745         if (!list_empty(&bss->list)) {
 746                 __cfg80211_unlink_bss(dev, bss);
 747                 dev->bss_generation++;
 748         }
 749         spin_unlock_bh(&dev->bss_lock);
 750 }
 751 EXPORT_SYMBOL(cfg80211_unlink_bss);
 752
 753 #ifdef CONFIG_CFG80211_WEXT
 754 int cfg80211_wext_siwscan(struct net_device *dev,
 755                           struct iw_request_info *info,
 756                           union iwreq_data *wrqu, char *extra)
 757 {
 758         struct cfg80211_registered_device *rdev;
 759         struct wiphy *wiphy;
 760         struct iw_scan_req *wreq = NULL;
 761         struct cfg80211_scan_request *creq = NULL;
 762         int i, err, n_channels = 0;
 763         enum ieee80211_band band;
 764
 765         if (!netif_running(dev))
 766                 return -ENETDOWN;
 767
 768         if (wrqu->data.length == sizeof(struct iw_scan_req))
 769                 wreq = (struct iw_scan_req *)extra;
 770
 771         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 772
 773         if (IS_ERR(rdev))
 774                 return PTR_ERR(rdev);
 775
 776         if (rdev->scan_req) {
 777                 err = -EBUSY;
 778                 goto out;
 779         }
 780
 781         wiphy = &rdev->wiphy;
 782
 783         /* Determine number of channels, needed to allocate creq */
 784         if (wreq && wreq->num_channels)
 785                 n_channels = wreq->num_channels;
 786         else {
 787                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 788                         if (wiphy->bands[band])
 789                                 n_channels += wiphy->bands[band]->n_channels;
 790         }
 791
 792         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 793                        n_channels * sizeof(void *),
 794                        GFP_ATOMIC);
 795         if (!creq) {
 796                 err = -ENOMEM;
 797                 goto out;
 798         }
 799
 800         creq->wiphy = wiphy;
 801         creq->dev = dev;
 802         /* SSIDs come after channels */
 803         creq->ssids = (void *)&creq->channels[n_channels];
 804         creq->n_channels = n_channels;
 805         creq->n_ssids = 1;
 806
 807         /* translate "Scan on frequencies" request */
 808         i = 0;
 809         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 810                 int j;
 811
 812                 if (!wiphy->bands[band])
 813                         continue;
 814
 815                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 816                         /* ignore disabled channels */
 817                         if (wiphy->bands[band]->channels[j].flags &
 818                                                 IEEE80211_CHAN_DISABLED)
 819                                 continue;
 820
 821                         /* If we have a wireless request structure and the
 822                          * wireless request specifies frequencies, then search
 823                          * for the matching hardware channel.
 824                          */
 825                         if (wreq && wreq->num_channels) {
 826                                 int k;
 827                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 828                                 for (k = 0; k < wreq->num_channels; k++) {
 829                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 830                                         if (wext_freq == wiphy_freq)
 831                                                 goto wext_freq_found;
 832                                 }
 833                                 goto wext_freq_not_found;
 834                         }
 835
 836                 wext_freq_found:
 837                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 838                         i++;
 839                 wext_freq_not_found: ;
 840                 }
 841         }
 842         /* No channels found? */
 843         if (!i) {
 844                 err = -EINVAL;
 845                 goto out;
 846         }
 847
 848         /* Set real number of channels specified in creq->channels[] */
 849         creq->n_channels = i;
 850
 851         /* translate "Scan for SSID" request */
 852         if (wreq) {
 853                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 854                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
 855                                 err = -EINVAL;
 856                                 goto out;
 857                         }
 858                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 859                         creq->ssids[0].ssid_len = wreq->essid_len;
 860                 }
 861                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 862                         creq->n_ssids = 0;
 863         }
 864
 865         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
 866                 if (wiphy->bands[i])
 867                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
 868
 869         rdev->scan_req = creq;
 870         err = rdev->ops->scan(wiphy, dev, creq);
 871         if (err) {
 872                 rdev->scan_req = NULL;
 873                 /* creq will be freed below */
 874         } else {
 875                 nl80211_send_scan_start(rdev, dev);
 876                 /* creq now owned by driver */
 877                 creq = NULL;
 878                 dev_hold(dev);
 879         }
 880  out:
 881         kfree(creq);
 882         cfg80211_unlock_rdev(rdev);
 883         return err;
 884 }
 885 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 886
 887 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 888                                    struct cfg80211_bss *bss,
 889                                    char **current_ev, char *end_buf)
 890 {
 891         u8 *pos, *end, *next;
 892         struct iw_event iwe;
 893
 894         if (!bss->information_elements ||
 895             !bss->len_information_elements)
 896                 return;
 897
 898         /*
 899          * If needed, fragment the IEs buffer (at IE boundaries) into short
 900          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 901          */
 902         pos = bss->information_elements;
 903         end = pos + bss->len_information_elements;
 904
 905         while (end - pos > IW_GENERIC_IE_MAX) {
 906                 next = pos + 2 + pos[1];
 907                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 908                         next = next + 2 + next[1];
 909
 910                 memset(&iwe, 0, sizeof(iwe));
 911                 iwe.cmd = IWEVGENIE;
 912                 iwe.u.data.length = next - pos;
 913                 *current_ev = iwe_stream_add_point(info, *current_ev,
 914                                                    end_buf, &iwe, pos);
 915
 916                 pos = next;
 917         }
 918
 919         if (end > pos) {
 920                 memset(&iwe, 0, sizeof(iwe));
 921                 iwe.cmd = IWEVGENIE;
 922                 iwe.u.data.length = end - pos;
 923                 *current_ev = iwe_stream_add_point(info, *current_ev,
 924                                                    end_buf, &iwe, pos);
 925         }
 926 }
 927
 928 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 929 {
 930         unsigned long end = jiffies;
 931
 932         if (end >= start)
 933                 return jiffies_to_msecs(end - start);
 934
 935         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 936 }
 937
 938 static char *
 939 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 940               struct cfg80211_internal_bss *bss, char *current_ev,
 941               char *end_buf)
 942 {
 943         struct iw_event iwe;
 944         u8 *buf, *cfg, *p;
 945         u8 *ie = bss->pub.information_elements;
 946         int rem = bss->pub.len_information_elements, i, sig;
 947         bool ismesh = false;
 948
 949         memset(&iwe, 0, sizeof(iwe));
 950         iwe.cmd = SIOCGIWAP;
 951         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 952         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 953         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 954                                           IW_EV_ADDR_LEN);
 955
 956         memset(&iwe, 0, sizeof(iwe));
 957         iwe.cmd = SIOCGIWFREQ;
 958         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 959         iwe.u.freq.e = 0;
 960         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 961                                           IW_EV_FREQ_LEN);
 962
 963         memset(&iwe, 0, sizeof(iwe));
 964         iwe.cmd = SIOCGIWFREQ;
 965         iwe.u.freq.m = bss->pub.channel->center_freq;
 966         iwe.u.freq.e = 6;
 967         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 968                                           IW_EV_FREQ_LEN);
 969
 970         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 971                 memset(&iwe, 0, sizeof(iwe));
 972                 iwe.cmd = IWEVQUAL;
 973                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 974                                      IW_QUAL_NOISE_INVALID |
 975                                      IW_QUAL_QUAL_UPDATED;
 976                 switch (wiphy->signal_type) {
 977                 case CFG80211_SIGNAL_TYPE_MBM:
 978                         sig = bss->pub.signal / 100;
 979                         iwe.u.qual.level = sig;
 980                         iwe.u.qual.updated |= IW_QUAL_DBM;
 981                         if (sig < -110)         /* rather bad */
 982                                 sig = -110;
 983                         else if (sig > -40)     /* perfect */
 984                                 sig = -40;
 985                         /* will give a range of 0 .. 70 */
 986                         iwe.u.qual.qual = sig + 110;
 987                         break;
 988                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 989                         iwe.u.qual.level = bss->pub.signal;
 990                         /* will give range 0 .. 100 */
 991                         iwe.u.qual.qual = bss->pub.signal;
 992                         break;
 993                 default:
 994                         /* not reached */
 995                         break;
 996                 }
 997                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 998                                                   &iwe, IW_EV_QUAL_LEN);
 999         }
1000
1001         memset(&iwe, 0, sizeof(iwe));
1002         iwe.cmd = SIOCGIWENCODE;
1003         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1004                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1005         else
1006                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1007         iwe.u.data.length = 0;
1008         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1009                                           &iwe, "");
1010
1011         while (rem >= 2) {
1012                 /* invalid data */
1013                 if (ie[1] > rem - 2)
1014                         break;
1015
1016                 switch (ie[0]) {
1017                 case WLAN_EID_SSID:
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_ID:
1026                         memset(&iwe, 0, sizeof(iwe));
1027                         iwe.cmd = SIOCGIWESSID;
1028                         iwe.u.data.length = ie[1];
1029                         iwe.u.data.flags = 1;
1030                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1031                                                           &iwe, ie + 2);
1032                         break;
1033                 case WLAN_EID_MESH_CONFIG:
1034                         ismesh = true;
1035                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1036                                 break;
1037                         buf = kmalloc(50, GFP_ATOMIC);
1038                         if (!buf)
1039                                 break;
1040                         cfg = ie + 2;
1041                         memset(&iwe, 0, sizeof(iwe));
1042                         iwe.cmd = IWEVCUSTOM;
1043                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1044                                 "0x%02X", cfg[0]);
1045                         iwe.u.data.length = strlen(buf);
1046                         current_ev = iwe_stream_add_point(info, current_ev,
1047                                                           end_buf,
1048                                                           &iwe, buf);
1049                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1050                                 cfg[1]);
1051                         iwe.u.data.length = strlen(buf);
1052                         current_ev = iwe_stream_add_point(info, current_ev,
1053                                                           end_buf,
1054                                                           &iwe, buf);
1055                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1056                                 cfg[2]);
1057                         iwe.u.data.length = strlen(buf);
1058                         current_ev = iwe_stream_add_point(info, current_ev,
1059                                                           end_buf,
1060                                                           &iwe, buf);
1061                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1062                         iwe.u.data.length = strlen(buf);
1063                         current_ev = iwe_stream_add_point(info, current_ev,
1064                                                           end_buf,
1065                                                           &iwe, buf);
1066                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1067                         iwe.u.data.length = strlen(buf);
1068                         current_ev = iwe_stream_add_point(info, current_ev,
1069                                                           end_buf,
1070                                                           &iwe, buf);
1071                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1072                         iwe.u.data.length = strlen(buf);
1073                         current_ev = iwe_stream_add_point(info, current_ev,
1074                                                           end_buf,
1075                                                           &iwe, buf);
1076                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1077                         iwe.u.data.length = strlen(buf);
1078                         current_ev = iwe_stream_add_point(info, current_ev,
1079                                                           end_buf,
1080                                                           &iwe, buf);
1081                         kfree(buf);
1082                         break;
1083                 case WLAN_EID_SUPP_RATES:
1084                 case WLAN_EID_EXT_SUPP_RATES:
1085                         /* display all supported rates in readable format */
1086                         p = current_ev + iwe_stream_lcp_len(info);
1087
1088                         memset(&iwe, 0, sizeof(iwe));
1089                         iwe.cmd = SIOCGIWRATE;
1090                         /* Those two flags are ignored... */
1091                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1092
1093                         for (i = 0; i < ie[1]; i++) {
1094                                 iwe.u.bitrate.value =
1095                                         ((ie[i + 2] & 0x7f) * 500000);
1096                                 p = iwe_stream_add_value(info, current_ev, p,
1097                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1098                         }
1099                         current_ev = p;
1100                         break;
1101                 }
1102                 rem -= ie[1] + 2;
1103                 ie += ie[1] + 2;
1104         }
1105
1106         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1107             ismesh) {
1108                 memset(&iwe, 0, sizeof(iwe));
1109                 iwe.cmd = SIOCGIWMODE;
1110                 if (ismesh)
1111                         iwe.u.mode = IW_MODE_MESH;
1112                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1113                         iwe.u.mode = IW_MODE_MASTER;
1114                 else
1115                         iwe.u.mode = IW_MODE_ADHOC;
1116                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1117                                                   &iwe, IW_EV_UINT_LEN);
1118         }
1119
1120         buf = kmalloc(30, GFP_ATOMIC);
1121         if (buf) {
1122                 memset(&iwe, 0, sizeof(iwe));
1123                 iwe.cmd = IWEVCUSTOM;
1124                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1125                 iwe.u.data.length = strlen(buf);
1126                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1127                                                   &iwe, buf);
1128                 memset(&iwe, 0, sizeof(iwe));
1129                 iwe.cmd = IWEVCUSTOM;
1130                 sprintf(buf, " Last beacon: %ums ago",
1131                         elapsed_jiffies_msecs(bss->ts));
1132                 iwe.u.data.length = strlen(buf);
1133                 current_ev = iwe_stream_add_point(info, current_ev,
1134                                                   end_buf, &iwe, buf);
1135                 kfree(buf);
1136         }
1137
1138         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1139
1140         return current_ev;
1141 }
1142
1143
1144 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1145                                   struct iw_request_info *info,
1146                                   char *buf, size_t len)
1147 {
1148         char *current_ev = buf;
1149         char *end_buf = buf + len;
1150         struct cfg80211_internal_bss *bss;
1151
1152         spin_lock_bh(&dev->bss_lock);
1153         cfg80211_bss_expire(dev);
1154
1155         list_for_each_entry(bss, &dev->bss_list, list) {
1156                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1157                         spin_unlock_bh(&dev->bss_lock);
1158                         return -E2BIG;
1159                 }
1160                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1161                                            current_ev, end_buf);
1162         }
1163         spin_unlock_bh(&dev->bss_lock);
1164         return current_ev - buf;
1165 }
1166
1167
1168 int cfg80211_wext_giwscan(struct net_device *dev,
1169                           struct iw_request_info *info,
1170                           struct iw_point *data, char *extra)
1171 {
1172         struct cfg80211_registered_device *rdev;
1173         int res;
1174
1175         if (!netif_running(dev))
1176                 return -ENETDOWN;
1177
1178         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1179
1180         if (IS_ERR(rdev))
1181                 return PTR_ERR(rdev);
1182
1183         if (rdev->scan_req) {
1184                 res = -EAGAIN;
1185                 goto out;
1186         }
1187
1188         res = ieee80211_scan_results(rdev, info, extra, data->length);
1189         data->length = 0;
1190         if (res >= 0) {
1191                 data->length = res;
1192                 res = 0;
1193         }
1194
1195  out:
1196         cfg80211_unlock_rdev(rdev);
1197         return res;
1198 }
1199 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1200 #endif