net/wireless/scan.c

   1 /*
   2  * cfg80211 scan result handling
   3  *
   4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
   5  */
   6 #include <linux/kernel.h>
   7 #include <linux/module.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/wireless.h>
  10 #include <linux/nl80211.h>
  11 #include <linux/etherdevice.h>
  12 #include <net/arp.h>
  13 #include <net/cfg80211.h>
  14 #include <net/iw_handler.h>
  15 #include "core.h"
  16 #include "nl80211.h"
  17 #include "wext-compat.h"
  18
  19 #define IEEE80211_SCAN_RESULT_EXPIRE    (15 * HZ)
  20
  21 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
  22 {
  23         struct cfg80211_scan_request *request;
  24         struct net_device *dev;
  25 #ifdef CONFIG_CFG80211_WEXT
  26         union iwreq_data wrqu;
  27 #endif
  28
  29         ASSERT_RDEV_LOCK(rdev);
  30
  31         request = rdev->scan_req;
  32
  33         if (!request)
  34                 return;
  35
  36         dev = request->dev;
  37
  38         /*
  39          * This must be before sending the other events!
  40          * Otherwise, wpa_supplicant gets completely confused with
  41          * wext events.
  42          */
  43         cfg80211_sme_scan_done(dev);
  44
  45         if (request->aborted)
  46                 nl80211_send_scan_aborted(rdev, dev);
  47         else
  48                 nl80211_send_scan_done(rdev, dev);
  49
  50 #ifdef CONFIG_CFG80211_WEXT
  51         if (!request->aborted) {
  52                 memset(&wrqu, 0, sizeof(wrqu));
  53
  54                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  55         }
  56 #endif
  57
  58         dev_put(dev);
  59
  60         rdev->scan_req = NULL;
  61
  62         /*
  63          * OK. If this is invoked with "leak" then we can't
  64          * free this ... but we've cleaned it up anyway. The
  65          * driver failed to call the scan_done callback, so
  66          * all bets are off, it might still be trying to use
  67          * the scan request or not ... if it accesses the dev
  68          * in there (it shouldn't anyway) then it may crash.
  69          */
  70         if (!leak)
  71                 kfree(request);
  72 }
  73
  74 void __cfg80211_scan_done(struct work_struct *wk)
  75 {
  76         struct cfg80211_registered_device *rdev;
  77
  78         rdev = container_of(wk, struct cfg80211_registered_device,
  79                             scan_done_wk);
  80
  81         cfg80211_lock_rdev(rdev);
  82         ___cfg80211_scan_done(rdev, false);
  83         cfg80211_unlock_rdev(rdev);
  84 }
  85
  86 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  87 {
  88         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  89
  90         request->aborted = aborted;
  91         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
  92 }
  93 EXPORT_SYMBOL(cfg80211_scan_done);
  94
  95 static void bss_release(struct kref *ref)
  96 {
  97         struct cfg80211_internal_bss *bss;
  98
  99         bss = container_of(ref, struct cfg80211_internal_bss, ref);
 100         if (bss->pub.free_priv)
 101                 bss->pub.free_priv(&bss->pub);
 102
 103         if (bss->beacon_ies_allocated)
 104                 kfree(bss->pub.beacon_ies);
 105         if (bss->proberesp_ies_allocated)
 106                 kfree(bss->pub.proberesp_ies);
 107
 108         BUG_ON(atomic_read(&bss->hold));
 109
 110         kfree(bss);
 111 }
 112
 113 /* must hold dev->bss_lock! */
 114 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 115                       unsigned long age_secs)
 116 {
 117         struct cfg80211_internal_bss *bss;
 118         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 119
 120         list_for_each_entry(bss, &dev->bss_list, list) {
 121                 bss->ts -= age_jiffies;
 122         }
 123 }
 124
 125 /* must hold dev->bss_lock! */
 126 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 127 {
 128         struct cfg80211_internal_bss *bss, *tmp;
 129         bool expired = false;
 130
 131         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 132                 if (atomic_read(&bss->hold))
 133                         continue;
 134                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 135                         continue;
 136                 list_del(&bss->list);
 137                 rb_erase(&bss->rbn, &dev->bss_tree);
 138                 kref_put(&bss->ref, bss_release);
 139                 expired = true;
 140         }
 141
 142         if (expired)
 143                 dev->bss_generation++;
 144 }
 145
 146 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 147 {
 148         while (len > 2 && ies[0] != eid) {
 149                 len -= ies[1] + 2;
 150                 ies += ies[1] + 2;
 151         }
 152         if (len < 2)
 153                 return NULL;
 154         if (len < 2 + ies[1])
 155                 return NULL;
 156         return ies;
 157 }
 158 EXPORT_SYMBOL(cfg80211_find_ie);
 159
 160 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 161 {
 162         const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
 163         const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
 164         int r;
 165
 166         if (!ie1 && !ie2)
 167                 return 0;
 168         if (!ie1 || !ie2)
 169                 return -1;
 170
 171         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 172         if (r == 0 && ie1[1] != ie2[1])
 173                 return ie2[1] - ie1[1];
 174         return r;
 175 }
 176
 177 static bool is_bss(struct cfg80211_bss *a,
 178                    const u8 *bssid,
 179                    const u8 *ssid, size_t ssid_len)
 180 {
 181         const u8 *ssidie;
 182
 183         if (bssid && compare_ether_addr(a->bssid, bssid))
 184                 return false;
 185
 186         if (!ssid)
 187                 return true;
 188
 189         ssidie = cfg80211_find_ie(WLAN_EID_SSID,
 190                                   a->information_elements,
 191                                   a->len_information_elements);
 192         if (!ssidie)
 193                 return false;
 194         if (ssidie[1] != ssid_len)
 195                 return false;
 196         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 197 }
 198
 199 static bool is_mesh(struct cfg80211_bss *a,
 200                     const u8 *meshid, size_t meshidlen,
 201                     const u8 *meshcfg)
 202 {
 203         const u8 *ie;
 204
 205         if (!is_zero_ether_addr(a->bssid))
 206                 return false;
 207
 208         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 209                               a->information_elements,
 210                               a->len_information_elements);
 211         if (!ie)
 212                 return false;
 213         if (ie[1] != meshidlen)
 214                 return false;
 215         if (memcmp(ie + 2, meshid, meshidlen))
 216                 return false;
 217
 218         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 219                               a->information_elements,
 220                               a->len_information_elements);
 221         if (!ie)
 222                 return false;
 223         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 224                 return false;
 225
 226         /*
 227          * Ignore mesh capability (last two bytes of the IE) when
 228          * comparing since that may differ between stations taking
 229          * part in the same mesh.
 230          */
 231         return memcmp(ie + 2, meshcfg,
 232             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
 233 }
 234
 235 static int cmp_bss(struct cfg80211_bss *a,
 236                    struct cfg80211_bss *b)
 237 {
 238         int r;
 239
 240         if (a->channel != b->channel)
 241                 return b->channel->center_freq - a->channel->center_freq;
 242
 243         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 244         if (r)
 245                 return r;
 246
 247         if (is_zero_ether_addr(a->bssid)) {
 248                 r = cmp_ies(WLAN_EID_MESH_ID,
 249                             a->information_elements,
 250                             a->len_information_elements,
 251                             b->information_elements,
 252                             b->len_information_elements);
 253                 if (r)
 254                         return r;
 255                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 256                                a->information_elements,
 257                                a->len_information_elements,
 258                                b->information_elements,
 259                                b->len_information_elements);
 260         }
 261
 262         return cmp_ies(WLAN_EID_SSID,
 263                        a->information_elements,
 264                        a->len_information_elements,
 265                        b->information_elements,
 266                        b->len_information_elements);
 267 }
 268
 269 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 270                                       struct ieee80211_channel *channel,
 271                                       const u8 *bssid,
 272                                       const u8 *ssid, size_t ssid_len,
 273                                       u16 capa_mask, u16 capa_val)
 274 {
 275         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 276         struct cfg80211_internal_bss *bss, *res = NULL;
 277
 278         spin_lock_bh(&dev->bss_lock);
 279
 280         list_for_each_entry(bss, &dev->bss_list, list) {
 281                 if ((bss->pub.capability & capa_mask) != capa_val)
 282                         continue;
 283                 if (channel && bss->pub.channel != channel)
 284                         continue;
 285                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 286                         res = bss;
 287                         kref_get(&res->ref);
 288                         break;
 289                 }
 290         }
 291
 292         spin_unlock_bh(&dev->bss_lock);
 293         if (!res)
 294                 return NULL;
 295         return &res->pub;
 296 }
 297 EXPORT_SYMBOL(cfg80211_get_bss);
 298
 299 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 300                                        struct ieee80211_channel *channel,
 301                                        const u8 *meshid, size_t meshidlen,
 302                                        const u8 *meshcfg)
 303 {
 304         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 305         struct cfg80211_internal_bss *bss, *res = NULL;
 306
 307         spin_lock_bh(&dev->bss_lock);
 308
 309         list_for_each_entry(bss, &dev->bss_list, list) {
 310                 if (channel && bss->pub.channel != channel)
 311                         continue;
 312                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 313                         res = bss;
 314                         kref_get(&res->ref);
 315                         break;
 316                 }
 317         }
 318
 319         spin_unlock_bh(&dev->bss_lock);
 320         if (!res)
 321                 return NULL;
 322         return &res->pub;
 323 }
 324 EXPORT_SYMBOL(cfg80211_get_mesh);
 325
 326
 327 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 328                           struct cfg80211_internal_bss *bss)
 329 {
 330         struct rb_node **p = &dev->bss_tree.rb_node;
 331         struct rb_node *parent = NULL;
 332         struct cfg80211_internal_bss *tbss;
 333         int cmp;
 334
 335         while (*p) {
 336                 parent = *p;
 337                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 338
 339                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 340
 341                 if (WARN_ON(!cmp)) {
 342                         /* will sort of leak this BSS */
 343                         return;
 344                 }
 345
 346                 if (cmp < 0)
 347                         p = &(*p)->rb_left;
 348                 else
 349                         p = &(*p)->rb_right;
 350         }
 351
 352         rb_link_node(&bss->rbn, parent, p);
 353         rb_insert_color(&bss->rbn, &dev->bss_tree);
 354 }
 355
 356 static struct cfg80211_internal_bss *
 357 rb_find_bss(struct cfg80211_registered_device *dev,
 358             struct cfg80211_internal_bss *res)
 359 {
 360         struct rb_node *n = dev->bss_tree.rb_node;
 361         struct cfg80211_internal_bss *bss;
 362         int r;
 363
 364         while (n) {
 365                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 366                 r = cmp_bss(&res->pub, &bss->pub);
 367
 368                 if (r == 0)
 369                         return bss;
 370                 else if (r < 0)
 371                         n = n->rb_left;
 372                 else
 373                         n = n->rb_right;
 374         }
 375
 376         return NULL;
 377 }
 378
 379 static struct cfg80211_internal_bss *
 380 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 381                     struct cfg80211_internal_bss *res)
 382 {
 383         struct cfg80211_internal_bss *found = NULL;
 384         const u8 *meshid, *meshcfg;
 385
 386         /*
 387          * The reference to "res" is donated to this function.
 388          */
 389
 390         if (WARN_ON(!res->pub.channel)) {
 391                 kref_put(&res->ref, bss_release);
 392                 return NULL;
 393         }
 394
 395         res->ts = jiffies;
 396
 397         if (is_zero_ether_addr(res->pub.bssid)) {
 398                 /* must be mesh, verify */
 399                 meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
 400                                           res->pub.information_elements,
 401                                           res->pub.len_information_elements);
 402                 meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 403                                            res->pub.information_elements,
 404                                            res->pub.len_information_elements);
 405                 if (!meshid || !meshcfg ||
 406                     meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
 407                         /* bogus mesh */
 408                         kref_put(&res->ref, bss_release);
 409                         return NULL;
 410                 }
 411         }
 412
 413         spin_lock_bh(&dev->bss_lock);
 414
 415         found = rb_find_bss(dev, res);
 416
 417         if (found) {
 418                 found->pub.beacon_interval = res->pub.beacon_interval;
 419                 found->pub.tsf = res->pub.tsf;
 420                 found->pub.signal = res->pub.signal;
 421                 found->pub.capability = res->pub.capability;
 422                 found->ts = res->ts;
 423
 424                 /* Update IEs */
 425                 if (res->pub.proberesp_ies) {
 426                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 427                         size_t ielen = res->pub.len_proberesp_ies;
 428
 429 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,28)
 430                         if (0) {
 431                                 used = 0; /* just to shut up the compiler */
 432 #else
 433                         if (found->pub.proberesp_ies &&
 434                             !found->proberesp_ies_allocated &&
 435                             ksize(found) >= used + ielen) {
 436 #endif
 437                                 memcpy(found->pub.proberesp_ies,
 438                                        res->pub.proberesp_ies, ielen);
 439                                 found->pub.len_proberesp_ies = ielen;
 440                         } else {
 441                                 u8 *ies = found->pub.proberesp_ies;
 442
 443                                 if (found->proberesp_ies_allocated)
 444                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 445                                 else
 446                                         ies = kmalloc(ielen, GFP_ATOMIC);
 447
 448                                 if (ies) {
 449                                         memcpy(ies, res->pub.proberesp_ies,
 450                                                ielen);
 451                                         found->proberesp_ies_allocated = true;
 452                                         found->pub.proberesp_ies = ies;
 453                                         found->pub.len_proberesp_ies = ielen;
 454                                 }
 455                         }
 456
 457                         /* Override possible earlier Beacon frame IEs */
 458                         found->pub.information_elements =
 459                                 found->pub.proberesp_ies;
 460                         found->pub.len_information_elements =
 461                                 found->pub.len_proberesp_ies;
 462                 }
 463                 if (res->pub.beacon_ies) {
 464                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 465                         size_t ielen = res->pub.len_beacon_ies;
 466
 467 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,28)
 468                         if (0) {
 469                                 used = 0; /* just to shut up the compiler */
 470 #else
 471                         if (found->pub.beacon_ies &&
 472                             !found->beacon_ies_allocated &&
 473                             ksize(found) >= used + ielen) {
 474 #endif
 475                                 memcpy(found->pub.beacon_ies,
 476                                        res->pub.beacon_ies, ielen);
 477                                 found->pub.len_beacon_ies = ielen;
 478                         } else {
 479                                 u8 *ies = found->pub.beacon_ies;
 480
 481                                 if (found->beacon_ies_allocated)
 482                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 483                                 else
 484                                         ies = kmalloc(ielen, GFP_ATOMIC);
 485
 486                                 if (ies) {
 487                                         memcpy(ies, res->pub.beacon_ies,
 488                                                ielen);
 489                                         found->beacon_ies_allocated = true;
 490                                         found->pub.beacon_ies = ies;
 491                                         found->pub.len_beacon_ies = ielen;
 492                                 }
 493                         }
 494                 }
 495
 496                 kref_put(&res->ref, bss_release);
 497         } else {
 498                 /* this "consumes" the reference */
 499                 list_add_tail(&res->list, &dev->bss_list);
 500                 rb_insert_bss(dev, res);
 501                 found = res;
 502         }
 503
 504         dev->bss_generation++;
 505         spin_unlock_bh(&dev->bss_lock);
 506
 507         kref_get(&found->ref);
 508         return found;
 509 }
 510
 511 struct cfg80211_bss*
 512 cfg80211_inform_bss(struct wiphy *wiphy,
 513                     struct ieee80211_channel *channel,
 514                     const u8 *bssid,
 515                     u64 timestamp, u16 capability, u16 beacon_interval,
 516                     const u8 *ie, size_t ielen,
 517                     s32 signal, gfp_t gfp)
 518 {
 519         struct cfg80211_internal_bss *res;
 520         size_t privsz;
 521
 522         if (WARN_ON(!wiphy))
 523                 return NULL;
 524
 525         privsz = wiphy->bss_priv_size;
 526
 527         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 528                         (signal < 0 || signal > 100)))
 529                 return NULL;
 530
 531         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 532         if (!res)
 533                 return NULL;
 534
 535         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 536         res->pub.channel = channel;
 537         res->pub.signal = signal;
 538         res->pub.tsf = timestamp;
 539         res->pub.beacon_interval = beacon_interval;
 540         res->pub.capability = capability;
 541         /*
 542          * Since we do not know here whether the IEs are from a Beacon or Probe
 543          * Response frame, we need to pick one of the options and only use it
 544          * with the driver that does not provide the full Beacon/Probe Response
 545          * frame. Use Beacon frame pointer to avoid indicating that this should
 546          * override the information_elements pointer should we have received an
 547          * earlier indication of Probe Response data.
 548          *
 549          * The initial buffer for the IEs is allocated with the BSS entry and
 550          * is located after the private area.
 551          */
 552         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
 553         memcpy(res->pub.beacon_ies, ie, ielen);
 554         res->pub.len_beacon_ies = ielen;
 555         res->pub.information_elements = res->pub.beacon_ies;
 556         res->pub.len_information_elements = res->pub.len_beacon_ies;
 557
 558         kref_init(&res->ref);
 559
 560         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 561         if (!res)
 562                 return NULL;
 563
 564         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 565                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 566
 567         /* cfg80211_bss_update gives us a referenced result */
 568         return &res->pub;
 569 }
 570 EXPORT_SYMBOL(cfg80211_inform_bss);
 571
 572 struct cfg80211_bss *
 573 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 574                           struct ieee80211_channel *channel,
 575                           struct ieee80211_mgmt *mgmt, size_t len,
 576                           s32 signal, gfp_t gfp)
 577 {
 578         struct cfg80211_internal_bss *res;
 579         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 580                                       u.probe_resp.variable);
 581         size_t privsz = wiphy->bss_priv_size;
 582
 583         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 584                     (signal < 0 || signal > 100)))
 585                 return NULL;
 586
 587         if (WARN_ON(!mgmt || !wiphy ||
 588                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 589                 return NULL;
 590
 591         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 592         if (!res)
 593                 return NULL;
 594
 595         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 596         res->pub.channel = channel;
 597         res->pub.signal = signal;
 598         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 599         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 600         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 601         /*
 602          * The initial buffer for the IEs is allocated with the BSS entry and
 603          * is located after the private area.
 604          */
 605         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 606                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
 607                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
 608                        ielen);
 609                 res->pub.len_proberesp_ies = ielen;
 610                 res->pub.information_elements = res->pub.proberesp_ies;
 611                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
 612         } else {
 613                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
 614                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
 615                 res->pub.len_beacon_ies = ielen;
 616                 res->pub.information_elements = res->pub.beacon_ies;
 617                 res->pub.len_information_elements = res->pub.len_beacon_ies;
 618         }
 619
 620         kref_init(&res->ref);
 621
 622         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 623         if (!res)
 624                 return NULL;
 625
 626         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 627                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 628
 629         /* cfg80211_bss_update gives us a referenced result */
 630         return &res->pub;
 631 }
 632 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 633
 634 void cfg80211_put_bss(struct cfg80211_bss *pub)
 635 {
 636         struct cfg80211_internal_bss *bss;
 637
 638         if (!pub)
 639                 return;
 640
 641         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 642         kref_put(&bss->ref, bss_release);
 643 }
 644 EXPORT_SYMBOL(cfg80211_put_bss);
 645
 646 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 647 {
 648         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 649         struct cfg80211_internal_bss *bss;
 650
 651         if (WARN_ON(!pub))
 652                 return;
 653
 654         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 655
 656         spin_lock_bh(&dev->bss_lock);
 657
 658         list_del(&bss->list);
 659         dev->bss_generation++;
 660         rb_erase(&bss->rbn, &dev->bss_tree);
 661
 662         spin_unlock_bh(&dev->bss_lock);
 663
 664         kref_put(&bss->ref, bss_release);
 665 }
 666 EXPORT_SYMBOL(cfg80211_unlink_bss);
 667
 668 #ifdef CONFIG_CFG80211_WEXT
 669 int cfg80211_wext_siwscan(struct net_device *dev,
 670                           struct iw_request_info *info,
 671                           union iwreq_data *wrqu, char *extra)
 672 {
 673         struct cfg80211_registered_device *rdev;
 674         struct wiphy *wiphy;
 675         struct iw_scan_req *wreq = NULL;
 676         struct cfg80211_scan_request *creq = NULL;
 677         int i, err, n_channels = 0;
 678         enum ieee80211_band band;
 679
 680         if (!netif_running(dev))
 681                 return -ENETDOWN;
 682
 683         if (wrqu->data.length == sizeof(struct iw_scan_req))
 684                 wreq = (struct iw_scan_req *)extra;
 685
 686         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 687
 688         if (IS_ERR(rdev))
 689                 return PTR_ERR(rdev);
 690
 691         if (rdev->scan_req) {
 692                 err = -EBUSY;
 693                 goto out;
 694         }
 695
 696         wiphy = &rdev->wiphy;
 697
 698         /* Determine number of channels, needed to allocate creq */
 699         if (wreq && wreq->num_channels)
 700                 n_channels = wreq->num_channels;
 701         else {
 702                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 703                         if (wiphy->bands[band])
 704                                 n_channels += wiphy->bands[band]->n_channels;
 705         }
 706
 707         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 708                        n_channels * sizeof(void *),
 709                        GFP_ATOMIC);
 710         if (!creq) {
 711                 err = -ENOMEM;
 712                 goto out;
 713         }
 714
 715         creq->wiphy = wiphy;
 716         creq->dev = dev;
 717         /* SSIDs come after channels */
 718         creq->ssids = (void *)&creq->channels[n_channels];
 719         creq->n_channels = n_channels;
 720         creq->n_ssids = 1;
 721
 722         /* translate "Scan on frequencies" request */
 723         i = 0;
 724         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 725                 int j;
 726
 727                 if (!wiphy->bands[band])
 728                         continue;
 729
 730                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 731                         /* ignore disabled channels */
 732                         if (wiphy->bands[band]->channels[j].flags &
 733                                                 IEEE80211_CHAN_DISABLED)
 734                                 continue;
 735
 736                         /* If we have a wireless request structure and the
 737                          * wireless request specifies frequencies, then search
 738                          * for the matching hardware channel.
 739                          */
 740                         if (wreq && wreq->num_channels) {
 741                                 int k;
 742                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 743                                 for (k = 0; k < wreq->num_channels; k++) {
 744                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 745                                         if (wext_freq == wiphy_freq)
 746                                                 goto wext_freq_found;
 747                                 }
 748                                 goto wext_freq_not_found;
 749                         }
 750
 751                 wext_freq_found:
 752                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 753                         i++;
 754                 wext_freq_not_found: ;
 755                 }
 756         }
 757         /* No channels found? */
 758         if (!i) {
 759                 err = -EINVAL;
 760                 goto out;
 761         }
 762
 763         /* Set real number of channels specified in creq->channels[] */
 764         creq->n_channels = i;
 765
 766         /* translate "Scan for SSID" request */
 767         if (wreq) {
 768                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 769                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
 770                                 err = -EINVAL;
 771                                 goto out;
 772                         }
 773                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 774                         creq->ssids[0].ssid_len = wreq->essid_len;
 775                 }
 776                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 777                         creq->n_ssids = 0;
 778         }
 779
 780         rdev->scan_req = creq;
 781         err = rdev->ops->scan(wiphy, dev, creq);
 782         if (err) {
 783                 rdev->scan_req = NULL;
 784                 /* creq will be freed below */
 785         } else {
 786                 nl80211_send_scan_start(rdev, dev);
 787                 /* creq now owned by driver */
 788                 creq = NULL;
 789                 dev_hold(dev);
 790         }
 791  out:
 792         kfree(creq);
 793         cfg80211_unlock_rdev(rdev);
 794         return err;
 795 }
 796 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 797
 798 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 799                                    struct cfg80211_bss *bss,
 800                                    char **current_ev, char *end_buf)
 801 {
 802         u8 *pos, *end, *next;
 803         struct iw_event iwe;
 804
 805         if (!bss->information_elements ||
 806             !bss->len_information_elements)
 807                 return;
 808
 809         /*
 810          * If needed, fragment the IEs buffer (at IE boundaries) into short
 811          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 812          */
 813         pos = bss->information_elements;
 814         end = pos + bss->len_information_elements;
 815
 816         while (end - pos > IW_GENERIC_IE_MAX) {
 817                 next = pos + 2 + pos[1];
 818                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 819                         next = next + 2 + next[1];
 820
 821                 memset(&iwe, 0, sizeof(iwe));
 822                 iwe.cmd = IWEVGENIE;
 823                 iwe.u.data.length = next - pos;
 824                 *current_ev = iwe_stream_add_point(info, *current_ev,
 825                                                    end_buf, &iwe, pos);
 826
 827                 pos = next;
 828         }
 829
 830         if (end > pos) {
 831                 memset(&iwe, 0, sizeof(iwe));
 832                 iwe.cmd = IWEVGENIE;
 833                 iwe.u.data.length = end - pos;
 834                 *current_ev = iwe_stream_add_point(info, *current_ev,
 835                                                    end_buf, &iwe, pos);
 836         }
 837 }
 838
 839 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 840 {
 841         unsigned long end = jiffies;
 842
 843         if (end >= start)
 844                 return jiffies_to_msecs(end - start);
 845
 846         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 847 }
 848
 849 static char *
 850 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 851               struct cfg80211_internal_bss *bss, char *current_ev,
 852               char *end_buf)
 853 {
 854         struct iw_event iwe;
 855         u8 *buf, *cfg, *p;
 856         u8 *ie = bss->pub.information_elements;
 857         int rem = bss->pub.len_information_elements, i, sig;
 858         bool ismesh = false;
 859
 860         memset(&iwe, 0, sizeof(iwe));
 861         iwe.cmd = SIOCGIWAP;
 862         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 863         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 864         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 865                                           IW_EV_ADDR_LEN);
 866
 867         memset(&iwe, 0, sizeof(iwe));
 868         iwe.cmd = SIOCGIWFREQ;
 869         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 870         iwe.u.freq.e = 0;
 871         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 872                                           IW_EV_FREQ_LEN);
 873
 874         memset(&iwe, 0, sizeof(iwe));
 875         iwe.cmd = SIOCGIWFREQ;
 876         iwe.u.freq.m = bss->pub.channel->center_freq;
 877         iwe.u.freq.e = 6;
 878         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 879                                           IW_EV_FREQ_LEN);
 880
 881         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 882                 memset(&iwe, 0, sizeof(iwe));
 883                 iwe.cmd = IWEVQUAL;
 884                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 885                                      IW_QUAL_NOISE_INVALID |
 886                                      IW_QUAL_QUAL_UPDATED;
 887                 switch (wiphy->signal_type) {
 888                 case CFG80211_SIGNAL_TYPE_MBM:
 889                         sig = bss->pub.signal / 100;
 890                         iwe.u.qual.level = sig;
 891                         iwe.u.qual.updated |= IW_QUAL_DBM;
 892                         if (sig < -110)         /* rather bad */
 893                                 sig = -110;
 894                         else if (sig > -40)     /* perfect */
 895                                 sig = -40;
 896                         /* will give a range of 0 .. 70 */
 897                         iwe.u.qual.qual = sig + 110;
 898                         break;
 899                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 900                         iwe.u.qual.level = bss->pub.signal;
 901                         /* will give range 0 .. 100 */
 902                         iwe.u.qual.qual = bss->pub.signal;
 903                         break;
 904                 default:
 905                         /* not reached */
 906                         break;
 907                 }
 908                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 909                                                   &iwe, IW_EV_QUAL_LEN);
 910         }
 911
 912         memset(&iwe, 0, sizeof(iwe));
 913         iwe.cmd = SIOCGIWENCODE;
 914         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 915                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 916         else
 917                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 918         iwe.u.data.length = 0;
 919         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 920                                           &iwe, "");
 921
 922         while (rem >= 2) {
 923                 /* invalid data */
 924                 if (ie[1] > rem - 2)
 925                         break;
 926
 927                 switch (ie[0]) {
 928                 case WLAN_EID_SSID:
 929                         memset(&iwe, 0, sizeof(iwe));
 930                         iwe.cmd = SIOCGIWESSID;
 931                         iwe.u.data.length = ie[1];
 932                         iwe.u.data.flags = 1;
 933                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 934                                                           &iwe, ie + 2);
 935                         break;
 936                 case WLAN_EID_MESH_ID:
 937                         memset(&iwe, 0, sizeof(iwe));
 938                         iwe.cmd = SIOCGIWESSID;
 939                         iwe.u.data.length = ie[1];
 940                         iwe.u.data.flags = 1;
 941                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 942                                                           &iwe, ie + 2);
 943                         break;
 944                 case WLAN_EID_MESH_CONFIG:
 945                         ismesh = true;
 946                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 947                                 break;
 948                         buf = kmalloc(50, GFP_ATOMIC);
 949                         if (!buf)
 950                                 break;
 951                         cfg = ie + 2;
 952                         memset(&iwe, 0, sizeof(iwe));
 953                         iwe.cmd = IWEVCUSTOM;
 954                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
 955                                 "0x%02X", cfg[0]);
 956                         iwe.u.data.length = strlen(buf);
 957                         current_ev = iwe_stream_add_point(info, current_ev,
 958                                                           end_buf,
 959                                                           &iwe, buf);
 960                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
 961                                 cfg[1]);
 962                         iwe.u.data.length = strlen(buf);
 963                         current_ev = iwe_stream_add_point(info, current_ev,
 964                                                           end_buf,
 965                                                           &iwe, buf);
 966                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
 967                                 cfg[2]);
 968                         iwe.u.data.length = strlen(buf);
 969                         current_ev = iwe_stream_add_point(info, current_ev,
 970                                                           end_buf,
 971                                                           &iwe, buf);
 972                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
 973                         iwe.u.data.length = strlen(buf);
 974                         current_ev = iwe_stream_add_point(info, current_ev,
 975                                                           end_buf,
 976                                                           &iwe, buf);
 977                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
 978                         iwe.u.data.length = strlen(buf);
 979                         current_ev = iwe_stream_add_point(info, current_ev,
 980                                                           end_buf,
 981                                                           &iwe, buf);
 982                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
 983                         iwe.u.data.length = strlen(buf);
 984                         current_ev = iwe_stream_add_point(info, current_ev,
 985                                                           end_buf,
 986                                                           &iwe, buf);
 987                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
 988                         iwe.u.data.length = strlen(buf);
 989                         current_ev = iwe_stream_add_point(info, current_ev,
 990                                                           end_buf,
 991                                                           &iwe, buf);
 992                         kfree(buf);
 993                         break;
 994                 case WLAN_EID_SUPP_RATES:
 995                 case WLAN_EID_EXT_SUPP_RATES:
 996                         /* display all supported rates in readable format */
 997                         p = current_ev + iwe_stream_lcp_len(info);
 998
 999                         memset(&iwe, 0, sizeof(iwe));
1000                         iwe.cmd = SIOCGIWRATE;
1001                         /* Those two flags are ignored... */
1002                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1003
1004                         for (i = 0; i < ie[1]; i++) {
1005                                 iwe.u.bitrate.value =
1006                                         ((ie[i + 2] & 0x7f) * 500000);
1007                                 p = iwe_stream_add_value(info, current_ev, p,
1008                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1009                         }
1010                         current_ev = p;
1011                         break;
1012                 }
1013                 rem -= ie[1] + 2;
1014                 ie += ie[1] + 2;
1015         }
1016
1017         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1018             ismesh) {
1019                 memset(&iwe, 0, sizeof(iwe));
1020                 iwe.cmd = SIOCGIWMODE;
1021                 if (ismesh)
1022                         iwe.u.mode = IW_MODE_MESH;
1023                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1024                         iwe.u.mode = IW_MODE_MASTER;
1025                 else
1026                         iwe.u.mode = IW_MODE_ADHOC;
1027                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1028                                                   &iwe, IW_EV_UINT_LEN);
1029         }
1030
1031         buf = kmalloc(30, GFP_ATOMIC);
1032         if (buf) {
1033                 memset(&iwe, 0, sizeof(iwe));
1034                 iwe.cmd = IWEVCUSTOM;
1035                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1036                 iwe.u.data.length = strlen(buf);
1037                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1038                                                   &iwe, buf);
1039                 memset(&iwe, 0, sizeof(iwe));
1040                 iwe.cmd = IWEVCUSTOM;
1041                 sprintf(buf, " Last beacon: %ums ago",
1042                         elapsed_jiffies_msecs(bss->ts));
1043                 iwe.u.data.length = strlen(buf);
1044                 current_ev = iwe_stream_add_point(info, current_ev,
1045                                                   end_buf, &iwe, buf);
1046                 kfree(buf);
1047         }
1048
1049         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1050
1051         return current_ev;
1052 }
1053
1054
1055 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1056                                   struct iw_request_info *info,
1057                                   char *buf, size_t len)
1058 {
1059         char *current_ev = buf;
1060         char *end_buf = buf + len;
1061         struct cfg80211_internal_bss *bss;
1062
1063         spin_lock_bh(&dev->bss_lock);
1064         cfg80211_bss_expire(dev);
1065
1066         list_for_each_entry(bss, &dev->bss_list, list) {
1067                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1068                         spin_unlock_bh(&dev->bss_lock);
1069                         return -E2BIG;
1070                 }
1071                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1072                                            current_ev, end_buf);
1073         }
1074         spin_unlock_bh(&dev->bss_lock);
1075         return current_ev - buf;
1076 }
1077
1078
1079 int cfg80211_wext_giwscan(struct net_device *dev,
1080                           struct iw_request_info *info,
1081                           struct iw_point *data, char *extra)
1082 {
1083         struct cfg80211_registered_device *rdev;
1084         int res;
1085
1086         if (!netif_running(dev))
1087                 return -ENETDOWN;
1088
1089         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1090
1091         if (IS_ERR(rdev))
1092                 return PTR_ERR(rdev);
1093
1094         if (rdev->scan_req) {
1095                 res = -EAGAIN;
1096                 goto out;
1097         }
1098
1099         res = ieee80211_scan_results(rdev, info, extra, data->length);
1100         data->length = 0;
1101         if (res >= 0) {
1102                 data->length = res;
1103                 res = 0;
1104         }
1105
1106  out:
1107         cfg80211_unlock_rdev(rdev);
1108         return res;
1109 }
1110 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1111 #endif