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         int err;
 136         struct net_device *dev;
 137
 138         lockdep_assert_held(&rdev->sched_scan_mtx);
 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_bss(struct cfg80211_bss *a)
 271 {
 272         const u8 *ie;
 273
 274         if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 275                 return false;
 276
 277         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 278                               a->information_elements,
 279                               a->len_information_elements);
 280         if (!ie)
 281                 return false;
 282
 283         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 284                               a->information_elements,
 285                               a->len_information_elements);
 286         if (!ie)
 287                 return false;
 288
 289         return true;
 290 }
 291
 292 static bool is_mesh(struct cfg80211_bss *a,
 293                     const u8 *meshid, size_t meshidlen,
 294                     const u8 *meshcfg)
 295 {
 296         const u8 *ie;
 297
 298         if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 299                 return false;
 300
 301         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 302                               a->information_elements,
 303                               a->len_information_elements);
 304         if (!ie)
 305                 return false;
 306         if (ie[1] != meshidlen)
 307                 return false;
 308         if (memcmp(ie + 2, meshid, meshidlen))
 309                 return false;
 310
 311         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 312                               a->information_elements,
 313                               a->len_information_elements);
 314         if (!ie)
 315                 return false;
 316         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 317                 return false;
 318
 319         /*
 320          * Ignore mesh capability (last two bytes of the IE) when
 321          * comparing since that may differ between stations taking
 322          * part in the same mesh.
 323          */
 324         return memcmp(ie + 2, meshcfg,
 325             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
 326 }
 327
 328 static int cmp_bss(struct cfg80211_bss *a,
 329                    struct cfg80211_bss *b)
 330 {
 331         int r;
 332
 333         if (a->channel != b->channel)
 334                 return b->channel->center_freq - a->channel->center_freq;
 335
 336         if (is_mesh_bss(a) && is_mesh_bss(b)) {
 337                 r = cmp_ies(WLAN_EID_MESH_ID,
 338                             a->information_elements,
 339                             a->len_information_elements,
 340                             b->information_elements,
 341                             b->len_information_elements);
 342                 if (r)
 343                         return r;
 344                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 345                                a->information_elements,
 346                                a->len_information_elements,
 347                                b->information_elements,
 348                                b->len_information_elements);
 349         }
 350
 351         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 352         if (r)
 353                 return r;
 354
 355         return cmp_ies(WLAN_EID_SSID,
 356                        a->information_elements,
 357                        a->len_information_elements,
 358                        b->information_elements,
 359                        b->len_information_elements);
 360 }
 361
 362 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 363                                       struct ieee80211_channel *channel,
 364                                       const u8 *bssid,
 365                                       const u8 *ssid, size_t ssid_len,
 366                                       u16 capa_mask, u16 capa_val)
 367 {
 368         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 369         struct cfg80211_internal_bss *bss, *res = NULL;
 370         unsigned long now = jiffies;
 371
 372         spin_lock_bh(&dev->bss_lock);
 373
 374         list_for_each_entry(bss, &dev->bss_list, list) {
 375                 if ((bss->pub.capability & capa_mask) != capa_val)
 376                         continue;
 377                 if (channel && bss->pub.channel != channel)
 378                         continue;
 379                 /* Don't get expired BSS structs */
 380                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 381                     !atomic_read(&bss->hold))
 382                         continue;
 383                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 384                         res = bss;
 385                         kref_get(&res->ref);
 386                         break;
 387                 }
 388         }
 389
 390         spin_unlock_bh(&dev->bss_lock);
 391         if (!res)
 392                 return NULL;
 393         return &res->pub;
 394 }
 395 EXPORT_SYMBOL(cfg80211_get_bss);
 396
 397 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 398                                        struct ieee80211_channel *channel,
 399                                        const u8 *meshid, size_t meshidlen,
 400                                        const u8 *meshcfg)
 401 {
 402         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 403         struct cfg80211_internal_bss *bss, *res = NULL;
 404
 405         spin_lock_bh(&dev->bss_lock);
 406
 407         list_for_each_entry(bss, &dev->bss_list, list) {
 408                 if (channel && bss->pub.channel != channel)
 409                         continue;
 410                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 411                         res = bss;
 412                         kref_get(&res->ref);
 413                         break;
 414                 }
 415         }
 416
 417         spin_unlock_bh(&dev->bss_lock);
 418         if (!res)
 419                 return NULL;
 420         return &res->pub;
 421 }
 422 EXPORT_SYMBOL(cfg80211_get_mesh);
 423
 424
 425 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 426                           struct cfg80211_internal_bss *bss)
 427 {
 428         struct rb_node **p = &dev->bss_tree.rb_node;
 429         struct rb_node *parent = NULL;
 430         struct cfg80211_internal_bss *tbss;
 431         int cmp;
 432
 433         while (*p) {
 434                 parent = *p;
 435                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 436
 437                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 438
 439                 if (WARN_ON(!cmp)) {
 440                         /* will sort of leak this BSS */
 441                         return;
 442                 }
 443
 444                 if (cmp < 0)
 445                         p = &(*p)->rb_left;
 446                 else
 447                         p = &(*p)->rb_right;
 448         }
 449
 450         rb_link_node(&bss->rbn, parent, p);
 451         rb_insert_color(&bss->rbn, &dev->bss_tree);
 452 }
 453
 454 static struct cfg80211_internal_bss *
 455 rb_find_bss(struct cfg80211_registered_device *dev,
 456             struct cfg80211_internal_bss *res)
 457 {
 458         struct rb_node *n = dev->bss_tree.rb_node;
 459         struct cfg80211_internal_bss *bss;
 460         int r;
 461
 462         while (n) {
 463                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 464                 r = cmp_bss(&res->pub, &bss->pub);
 465
 466                 if (r == 0)
 467                         return bss;
 468                 else if (r < 0)
 469                         n = n->rb_left;
 470                 else
 471                         n = n->rb_right;
 472         }
 473
 474         return NULL;
 475 }
 476
 477 static struct cfg80211_internal_bss *
 478 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 479                     struct cfg80211_internal_bss *res)
 480 {
 481         struct cfg80211_internal_bss *found = NULL;
 482
 483         /*
 484          * The reference to "res" is donated to this function.
 485          */
 486
 487         if (WARN_ON(!res->pub.channel)) {
 488                 kref_put(&res->ref, bss_release);
 489                 return NULL;
 490         }
 491
 492         res->ts = jiffies;
 493
 494         spin_lock_bh(&dev->bss_lock);
 495
 496         found = rb_find_bss(dev, res);
 497
 498         if (found) {
 499                 found->pub.beacon_interval = res->pub.beacon_interval;
 500                 found->pub.tsf = res->pub.tsf;
 501                 found->pub.signal = res->pub.signal;
 502                 found->pub.capability = res->pub.capability;
 503                 found->ts = res->ts;
 504
 505                 /* Update IEs */
 506                 if (res->pub.proberesp_ies) {
 507                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 508                         size_t ielen = res->pub.len_proberesp_ies;
 509
 510                         if (found->pub.proberesp_ies &&
 511                             !found->proberesp_ies_allocated &&
 512                             ksize(found) >= used + ielen) {
 513                                 memcpy(found->pub.proberesp_ies,
 514                                        res->pub.proberesp_ies, ielen);
 515                                 found->pub.len_proberesp_ies = ielen;
 516                         } else {
 517                                 u8 *ies = found->pub.proberesp_ies;
 518
 519                                 if (found->proberesp_ies_allocated)
 520                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 521                                 else
 522                                         ies = kmalloc(ielen, GFP_ATOMIC);
 523
 524                                 if (ies) {
 525                                         memcpy(ies, res->pub.proberesp_ies,
 526                                                ielen);
 527                                         found->proberesp_ies_allocated = true;
 528                                         found->pub.proberesp_ies = ies;
 529                                         found->pub.len_proberesp_ies = ielen;
 530                                 }
 531                         }
 532
 533                         /* Override possible earlier Beacon frame IEs */
 534                         found->pub.information_elements =
 535                                 found->pub.proberesp_ies;
 536                         found->pub.len_information_elements =
 537                                 found->pub.len_proberesp_ies;
 538                 }
 539                 if (res->pub.beacon_ies) {
 540                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 541                         size_t ielen = res->pub.len_beacon_ies;
 542                         bool information_elements_is_beacon_ies =
 543                                 (found->pub.information_elements ==
 544                                  found->pub.beacon_ies);
 545
 546                         if (found->pub.beacon_ies &&
 547                             !found->beacon_ies_allocated &&
 548                             ksize(found) >= used + ielen) {
 549                                 memcpy(found->pub.beacon_ies,
 550                                        res->pub.beacon_ies, ielen);
 551                                 found->pub.len_beacon_ies = ielen;
 552                         } else {
 553                                 u8 *ies = found->pub.beacon_ies;
 554
 555                                 if (found->beacon_ies_allocated)
 556                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 557                                 else
 558                                         ies = kmalloc(ielen, GFP_ATOMIC);
 559
 560                                 if (ies) {
 561                                         memcpy(ies, res->pub.beacon_ies,
 562                                                ielen);
 563                                         found->beacon_ies_allocated = true;
 564                                         found->pub.beacon_ies = ies;
 565                                         found->pub.len_beacon_ies = ielen;
 566                                 }
 567                         }
 568
 569                         /* Override IEs if they were from a beacon before */
 570                         if (information_elements_is_beacon_ies) {
 571                                 found->pub.information_elements =
 572                                         found->pub.beacon_ies;
 573                                 found->pub.len_information_elements =
 574                                         found->pub.len_beacon_ies;
 575                         }
 576                 }
 577
 578                 kref_put(&res->ref, bss_release);
 579         } else {
 580                 /* this "consumes" the reference */
 581                 list_add_tail(&res->list, &dev->bss_list);
 582                 rb_insert_bss(dev, res);
 583                 found = res;
 584         }
 585
 586         dev->bss_generation++;
 587         spin_unlock_bh(&dev->bss_lock);
 588
 589         kref_get(&found->ref);
 590         return found;
 591 }
 592
 593 struct cfg80211_bss*
 594 cfg80211_inform_bss(struct wiphy *wiphy,
 595                     struct ieee80211_channel *channel,
 596                     const u8 *bssid,
 597                     u64 timestamp, u16 capability, u16 beacon_interval,
 598                     const u8 *ie, size_t ielen,
 599                     s32 signal, gfp_t gfp)
 600 {
 601         struct cfg80211_internal_bss *res;
 602         size_t privsz;
 603
 604         if (WARN_ON(!wiphy))
 605                 return NULL;
 606
 607         privsz = wiphy->bss_priv_size;
 608
 609         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 610                         (signal < 0 || signal > 100)))
 611                 return NULL;
 612
 613         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 614         if (!res)
 615                 return NULL;
 616
 617         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 618         res->pub.channel = channel;
 619         res->pub.signal = signal;
 620         res->pub.tsf = timestamp;
 621         res->pub.beacon_interval = beacon_interval;
 622         res->pub.capability = capability;
 623         /*
 624          * Since we do not know here whether the IEs are from a Beacon or Probe
 625          * Response frame, we need to pick one of the options and only use it
 626          * with the driver that does not provide the full Beacon/Probe Response
 627          * frame. Use Beacon frame pointer to avoid indicating that this should
 628          * override the information_elements pointer should we have received an
 629          * earlier indication of Probe Response data.
 630          *
 631          * The initial buffer for the IEs is allocated with the BSS entry and
 632          * is located after the private area.
 633          */
 634         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
 635         memcpy(res->pub.beacon_ies, ie, ielen);
 636         res->pub.len_beacon_ies = ielen;
 637         res->pub.information_elements = res->pub.beacon_ies;
 638         res->pub.len_information_elements = res->pub.len_beacon_ies;
 639
 640         kref_init(&res->ref);
 641
 642         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 643         if (!res)
 644                 return NULL;
 645
 646         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 647                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 648
 649         /* cfg80211_bss_update gives us a referenced result */
 650         return &res->pub;
 651 }
 652 EXPORT_SYMBOL(cfg80211_inform_bss);
 653
 654 struct cfg80211_bss *
 655 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 656                           struct ieee80211_channel *channel,
 657                           struct ieee80211_mgmt *mgmt, size_t len,
 658                           s32 signal, gfp_t gfp)
 659 {
 660         struct cfg80211_internal_bss *res;
 661         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 662                                       u.probe_resp.variable);
 663         size_t privsz;
 664
 665         if (WARN_ON(!mgmt))
 666                 return NULL;
 667
 668         if (WARN_ON(!wiphy))
 669                 return NULL;
 670
 671         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 672                     (signal < 0 || signal > 100)))
 673                 return NULL;
 674
 675         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 676                 return NULL;
 677
 678         privsz = wiphy->bss_priv_size;
 679
 680         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 681         if (!res)
 682                 return NULL;
 683
 684         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 685         res->pub.channel = channel;
 686         res->pub.signal = signal;
 687         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 688         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 689         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 690         /*
 691          * The initial buffer for the IEs is allocated with the BSS entry and
 692          * is located after the private area.
 693          */
 694         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 695                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
 696                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
 697                        ielen);
 698                 res->pub.len_proberesp_ies = ielen;
 699                 res->pub.information_elements = res->pub.proberesp_ies;
 700                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
 701         } else {
 702                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
 703                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
 704                 res->pub.len_beacon_ies = ielen;
 705                 res->pub.information_elements = res->pub.beacon_ies;
 706                 res->pub.len_information_elements = res->pub.len_beacon_ies;
 707         }
 708
 709         kref_init(&res->ref);
 710
 711         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 712         if (!res)
 713                 return NULL;
 714
 715         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 716                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 717
 718         /* cfg80211_bss_update gives us a referenced result */
 719         return &res->pub;
 720 }
 721 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 722
 723 void cfg80211_put_bss(struct cfg80211_bss *pub)
 724 {
 725         struct cfg80211_internal_bss *bss;
 726
 727         if (!pub)
 728                 return;
 729
 730         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 731         kref_put(&bss->ref, bss_release);
 732 }
 733 EXPORT_SYMBOL(cfg80211_put_bss);
 734
 735 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 736 {
 737         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 738         struct cfg80211_internal_bss *bss;
 739
 740         if (WARN_ON(!pub))
 741                 return;
 742
 743         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 744
 745         spin_lock_bh(&dev->bss_lock);
 746         if (!list_empty(&bss->list)) {
 747                 __cfg80211_unlink_bss(dev, bss);
 748                 dev->bss_generation++;
 749         }
 750         spin_unlock_bh(&dev->bss_lock);
 751 }
 752 EXPORT_SYMBOL(cfg80211_unlink_bss);
 753
 754 #ifdef CONFIG_CFG80211_WEXT
 755 int cfg80211_wext_siwscan(struct net_device *dev,
 756                           struct iw_request_info *info,
 757                           union iwreq_data *wrqu, char *extra)
 758 {
 759         struct cfg80211_registered_device *rdev;
 760         struct wiphy *wiphy;
 761         struct iw_scan_req *wreq = NULL;
 762         struct cfg80211_scan_request *creq = NULL;
 763         int i, err, n_channels = 0;
 764         enum ieee80211_band band;
 765
 766         if (!netif_running(dev))
 767                 return -ENETDOWN;
 768
 769         if (wrqu->data.length == sizeof(struct iw_scan_req))
 770                 wreq = (struct iw_scan_req *)extra;
 771
 772         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 773
 774         if (IS_ERR(rdev))
 775                 return PTR_ERR(rdev);
 776
 777         if (rdev->scan_req) {
 778                 err = -EBUSY;
 779                 goto out;
 780         }
 781
 782         wiphy = &rdev->wiphy;
 783
 784         /* Determine number of channels, needed to allocate creq */
 785         if (wreq && wreq->num_channels)
 786                 n_channels = wreq->num_channels;
 787         else {
 788                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 789                         if (wiphy->bands[band])
 790                                 n_channels += wiphy->bands[band]->n_channels;
 791         }
 792
 793         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 794                        n_channels * sizeof(void *),
 795                        GFP_ATOMIC);
 796         if (!creq) {
 797                 err = -ENOMEM;
 798                 goto out;
 799         }
 800
 801         creq->wiphy = wiphy;
 802         creq->dev = dev;
 803         /* SSIDs come after channels */
 804         creq->ssids = (void *)&creq->channels[n_channels];
 805         creq->n_channels = n_channels;
 806         creq->n_ssids = 1;
 807
 808         /* translate "Scan on frequencies" request */
 809         i = 0;
 810         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 811                 int j;
 812
 813                 if (!wiphy->bands[band])
 814                         continue;
 815
 816                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 817                         /* ignore disabled channels */
 818                         if (wiphy->bands[band]->channels[j].flags &
 819                                                 IEEE80211_CHAN_DISABLED)
 820                                 continue;
 821
 822                         /* If we have a wireless request structure and the
 823                          * wireless request specifies frequencies, then search
 824                          * for the matching hardware channel.
 825                          */
 826                         if (wreq && wreq->num_channels) {
 827                                 int k;
 828                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 829                                 for (k = 0; k < wreq->num_channels; k++) {
 830                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 831                                         if (wext_freq == wiphy_freq)
 832                                                 goto wext_freq_found;
 833                                 }
 834                                 goto wext_freq_not_found;
 835                         }
 836
 837                 wext_freq_found:
 838                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 839                         i++;
 840                 wext_freq_not_found: ;
 841                 }
 842         }
 843         /* No channels found? */
 844         if (!i) {
 845                 err = -EINVAL;
 846                 goto out;
 847         }
 848
 849         /* Set real number of channels specified in creq->channels[] */
 850         creq->n_channels = i;
 851
 852         /* translate "Scan for SSID" request */
 853         if (wreq) {
 854                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 855                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
 856                                 err = -EINVAL;
 857                                 goto out;
 858                         }
 859                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 860                         creq->ssids[0].ssid_len = wreq->essid_len;
 861                 }
 862                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 863                         creq->n_ssids = 0;
 864         }
 865
 866         rdev->scan_req = creq;
 867         err = rdev->ops->scan(wiphy, dev, creq);
 868         if (err) {
 869                 rdev->scan_req = NULL;
 870                 /* creq will be freed below */
 871         } else {
 872                 nl80211_send_scan_start(rdev, dev);
 873                 /* creq now owned by driver */
 874                 creq = NULL;
 875                 dev_hold(dev);
 876         }
 877  out:
 878         kfree(creq);
 879         cfg80211_unlock_rdev(rdev);
 880         return err;
 881 }
 882 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 883
 884 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 885                                    struct cfg80211_bss *bss,
 886                                    char **current_ev, char *end_buf)
 887 {
 888         u8 *pos, *end, *next;
 889         struct iw_event iwe;
 890
 891         if (!bss->information_elements ||
 892             !bss->len_information_elements)
 893                 return;
 894
 895         /*
 896          * If needed, fragment the IEs buffer (at IE boundaries) into short
 897          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 898          */
 899         pos = bss->information_elements;
 900         end = pos + bss->len_information_elements;
 901
 902         while (end - pos > IW_GENERIC_IE_MAX) {
 903                 next = pos + 2 + pos[1];
 904                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 905                         next = next + 2 + next[1];
 906
 907                 memset(&iwe, 0, sizeof(iwe));
 908                 iwe.cmd = IWEVGENIE;
 909                 iwe.u.data.length = next - pos;
 910                 *current_ev = iwe_stream_add_point(info, *current_ev,
 911                                                    end_buf, &iwe, pos);
 912
 913                 pos = next;
 914         }
 915
 916         if (end > pos) {
 917                 memset(&iwe, 0, sizeof(iwe));
 918                 iwe.cmd = IWEVGENIE;
 919                 iwe.u.data.length = end - pos;
 920                 *current_ev = iwe_stream_add_point(info, *current_ev,
 921                                                    end_buf, &iwe, pos);
 922         }
 923 }
 924
 925 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 926 {
 927         unsigned long end = jiffies;
 928
 929         if (end >= start)
 930                 return jiffies_to_msecs(end - start);
 931
 932         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 933 }
 934
 935 static char *
 936 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 937               struct cfg80211_internal_bss *bss, char *current_ev,
 938               char *end_buf)
 939 {
 940         struct iw_event iwe;
 941         u8 *buf, *cfg, *p;
 942         u8 *ie = bss->pub.information_elements;
 943         int rem = bss->pub.len_information_elements, i, sig;
 944         bool ismesh = false;
 945
 946         memset(&iwe, 0, sizeof(iwe));
 947         iwe.cmd = SIOCGIWAP;
 948         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 949         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 950         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 951                                           IW_EV_ADDR_LEN);
 952
 953         memset(&iwe, 0, sizeof(iwe));
 954         iwe.cmd = SIOCGIWFREQ;
 955         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 956         iwe.u.freq.e = 0;
 957         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 958                                           IW_EV_FREQ_LEN);
 959
 960         memset(&iwe, 0, sizeof(iwe));
 961         iwe.cmd = SIOCGIWFREQ;
 962         iwe.u.freq.m = bss->pub.channel->center_freq;
 963         iwe.u.freq.e = 6;
 964         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 965                                           IW_EV_FREQ_LEN);
 966
 967         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 968                 memset(&iwe, 0, sizeof(iwe));
 969                 iwe.cmd = IWEVQUAL;
 970                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 971                                      IW_QUAL_NOISE_INVALID |
 972                                      IW_QUAL_QUAL_UPDATED;
 973                 switch (wiphy->signal_type) {
 974                 case CFG80211_SIGNAL_TYPE_MBM:
 975                         sig = bss->pub.signal / 100;
 976                         iwe.u.qual.level = sig;
 977                         iwe.u.qual.updated |= IW_QUAL_DBM;
 978                         if (sig < -110)         /* rather bad */
 979                                 sig = -110;
 980                         else if (sig > -40)     /* perfect */
 981                                 sig = -40;
 982                         /* will give a range of 0 .. 70 */
 983                         iwe.u.qual.qual = sig + 110;
 984                         break;
 985                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 986                         iwe.u.qual.level = bss->pub.signal;
 987                         /* will give range 0 .. 100 */
 988                         iwe.u.qual.qual = bss->pub.signal;
 989                         break;
 990                 default:
 991                         /* not reached */
 992                         break;
 993                 }
 994                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 995                                                   &iwe, IW_EV_QUAL_LEN);
 996         }
 997
 998         memset(&iwe, 0, sizeof(iwe));
 999         iwe.cmd = SIOCGIWENCODE;
1000         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1001                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1002         else
1003                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1004         iwe.u.data.length = 0;
1005         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1006                                           &iwe, "");
1007
1008         while (rem >= 2) {
1009                 /* invalid data */
1010                 if (ie[1] > rem - 2)
1011                         break;
1012
1013                 switch (ie[0]) {
1014                 case WLAN_EID_SSID:
1015                         memset(&iwe, 0, sizeof(iwe));
1016                         iwe.cmd = SIOCGIWESSID;
1017                         iwe.u.data.length = ie[1];
1018                         iwe.u.data.flags = 1;
1019                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1020                                                           &iwe, ie + 2);
1021                         break;
1022                 case WLAN_EID_MESH_ID:
1023                         memset(&iwe, 0, sizeof(iwe));
1024                         iwe.cmd = SIOCGIWESSID;
1025                         iwe.u.data.length = ie[1];
1026                         iwe.u.data.flags = 1;
1027                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1028                                                           &iwe, ie + 2);
1029                         break;
1030                 case WLAN_EID_MESH_CONFIG:
1031                         ismesh = true;
1032                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1033                                 break;
1034                         buf = kmalloc(50, GFP_ATOMIC);
1035                         if (!buf)
1036                                 break;
1037                         cfg = ie + 2;
1038                         memset(&iwe, 0, sizeof(iwe));
1039                         iwe.cmd = IWEVCUSTOM;
1040                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1041                                 "0x%02X", cfg[0]);
1042                         iwe.u.data.length = strlen(buf);
1043                         current_ev = iwe_stream_add_point(info, current_ev,
1044                                                           end_buf,
1045                                                           &iwe, buf);
1046                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1047                                 cfg[1]);
1048                         iwe.u.data.length = strlen(buf);
1049                         current_ev = iwe_stream_add_point(info, current_ev,
1050                                                           end_buf,
1051                                                           &iwe, buf);
1052                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1053                                 cfg[2]);
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, "Synchronization ID: 0x%02X", cfg[3]);
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, "Authentication ID: 0x%02X", cfg[4]);
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, "Formation Info: 0x%02X", cfg[5]);
1069                         iwe.u.data.length = strlen(buf);
1070                         current_ev = iwe_stream_add_point(info, current_ev,
1071                                                           end_buf,
1072                                                           &iwe, buf);
1073                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1074                         iwe.u.data.length = strlen(buf);
1075                         current_ev = iwe_stream_add_point(info, current_ev,
1076                                                           end_buf,
1077                                                           &iwe, buf);
1078                         kfree(buf);
1079                         break;
1080                 case WLAN_EID_SUPP_RATES:
1081                 case WLAN_EID_EXT_SUPP_RATES:
1082                         /* display all supported rates in readable format */
1083                         p = current_ev + iwe_stream_lcp_len(info);
1084
1085                         memset(&iwe, 0, sizeof(iwe));
1086                         iwe.cmd = SIOCGIWRATE;
1087                         /* Those two flags are ignored... */
1088                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1089
1090                         for (i = 0; i < ie[1]; i++) {
1091                                 iwe.u.bitrate.value =
1092                                         ((ie[i + 2] & 0x7f) * 500000);
1093                                 p = iwe_stream_add_value(info, current_ev, p,
1094                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1095                         }
1096                         current_ev = p;
1097                         break;
1098                 }
1099                 rem -= ie[1] + 2;
1100                 ie += ie[1] + 2;
1101         }
1102
1103         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1104             ismesh) {
1105                 memset(&iwe, 0, sizeof(iwe));
1106                 iwe.cmd = SIOCGIWMODE;
1107                 if (ismesh)
1108                         iwe.u.mode = IW_MODE_MESH;
1109                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1110                         iwe.u.mode = IW_MODE_MASTER;
1111                 else
1112                         iwe.u.mode = IW_MODE_ADHOC;
1113                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1114                                                   &iwe, IW_EV_UINT_LEN);
1115         }
1116
1117         buf = kmalloc(30, GFP_ATOMIC);
1118         if (buf) {
1119                 memset(&iwe, 0, sizeof(iwe));
1120                 iwe.cmd = IWEVCUSTOM;
1121                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1122                 iwe.u.data.length = strlen(buf);
1123                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1124                                                   &iwe, buf);
1125                 memset(&iwe, 0, sizeof(iwe));
1126                 iwe.cmd = IWEVCUSTOM;
1127                 sprintf(buf, " Last beacon: %ums ago",
1128                         elapsed_jiffies_msecs(bss->ts));
1129                 iwe.u.data.length = strlen(buf);
1130                 current_ev = iwe_stream_add_point(info, current_ev,
1131                                                   end_buf, &iwe, buf);
1132                 kfree(buf);
1133         }
1134
1135         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1136
1137         return current_ev;
1138 }
1139
1140
1141 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1142                                   struct iw_request_info *info,
1143                                   char *buf, size_t len)
1144 {
1145         char *current_ev = buf;
1146         char *end_buf = buf + len;
1147         struct cfg80211_internal_bss *bss;
1148
1149         spin_lock_bh(&dev->bss_lock);
1150         cfg80211_bss_expire(dev);
1151
1152         list_for_each_entry(bss, &dev->bss_list, list) {
1153                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1154                         spin_unlock_bh(&dev->bss_lock);
1155                         return -E2BIG;
1156                 }
1157                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1158                                            current_ev, end_buf);
1159         }
1160         spin_unlock_bh(&dev->bss_lock);
1161         return current_ev - buf;
1162 }
1163
1164
1165 int cfg80211_wext_giwscan(struct net_device *dev,
1166                           struct iw_request_info *info,
1167                           struct iw_point *data, char *extra)
1168 {
1169         struct cfg80211_registered_device *rdev;
1170         int res;
1171
1172         if (!netif_running(dev))
1173                 return -ENETDOWN;
1174
1175         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1176
1177         if (IS_ERR(rdev))
1178                 return PTR_ERR(rdev);
1179
1180         if (rdev->scan_req) {
1181                 res = -EAGAIN;
1182                 goto out;
1183         }
1184
1185         res = ieee80211_scan_results(rdev, info, extra, data->length);
1186         data->length = 0;
1187         if (res >= 0) {
1188                 data->length = res;
1189                 res = 0;
1190         }
1191
1192  out:
1193         cfg80211_unlock_rdev(rdev);
1194         return res;
1195 }
1196 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1197 #endif