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_WIRELESS_EXT
  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_WIRELESS_EXT
  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         schedule_work(&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->ies_allocated)
 104                 kfree(bss->pub.information_elements);
 105
 106         BUG_ON(atomic_read(&bss->hold));
 107
 108         kfree(bss);
 109 }
 110
 111 /* must hold dev->bss_lock! */
 112 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 113                       unsigned long age_secs)
 114 {
 115         struct cfg80211_internal_bss *bss;
 116         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 117
 118         list_for_each_entry(bss, &dev->bss_list, list) {
 119                 bss->ts -= age_jiffies;
 120         }
 121 }
 122
 123 /* must hold dev->bss_lock! */
 124 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 125 {
 126         struct cfg80211_internal_bss *bss, *tmp;
 127         bool expired = false;
 128
 129         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 130                 if (atomic_read(&bss->hold))
 131                         continue;
 132                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 133                         continue;
 134                 list_del(&bss->list);
 135                 rb_erase(&bss->rbn, &dev->bss_tree);
 136                 kref_put(&bss->ref, bss_release);
 137                 expired = true;
 138         }
 139
 140         if (expired)
 141                 dev->bss_generation++;
 142 }
 143
 144 static u8 *find_ie(u8 num, u8 *ies, int len)
 145 {
 146         while (len > 2 && ies[0] != num) {
 147                 len -= ies[1] + 2;
 148                 ies += ies[1] + 2;
 149         }
 150         if (len < 2)
 151                 return NULL;
 152         if (len < 2 + ies[1])
 153                 return NULL;
 154         return ies;
 155 }
 156
 157 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 158 {
 159         const u8 *ie1 = find_ie(num, ies1, len1);
 160         const u8 *ie2 = find_ie(num, ies2, len2);
 161         int r;
 162
 163         if (!ie1 && !ie2)
 164                 return 0;
 165         if (!ie1 || !ie2)
 166                 return -1;
 167
 168         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 169         if (r == 0 && ie1[1] != ie2[1])
 170                 return ie2[1] - ie1[1];
 171         return r;
 172 }
 173
 174 static bool is_bss(struct cfg80211_bss *a,
 175                    const u8 *bssid,
 176                    const u8 *ssid, size_t ssid_len)
 177 {
 178         const u8 *ssidie;
 179
 180         if (bssid && compare_ether_addr(a->bssid, bssid))
 181                 return false;
 182
 183         if (!ssid)
 184                 return true;
 185
 186         ssidie = find_ie(WLAN_EID_SSID,
 187                          a->information_elements,
 188                          a->len_information_elements);
 189         if (!ssidie)
 190                 return false;
 191         if (ssidie[1] != ssid_len)
 192                 return false;
 193         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 194 }
 195
 196 static bool is_mesh(struct cfg80211_bss *a,
 197                     const u8 *meshid, size_t meshidlen,
 198                     const u8 *meshcfg)
 199 {
 200         const u8 *ie;
 201
 202         if (!is_zero_ether_addr(a->bssid))
 203                 return false;
 204
 205         ie = find_ie(WLAN_EID_MESH_ID,
 206                      a->information_elements,
 207                      a->len_information_elements);
 208         if (!ie)
 209                 return false;
 210         if (ie[1] != meshidlen)
 211                 return false;
 212         if (memcmp(ie + 2, meshid, meshidlen))
 213                 return false;
 214
 215         ie = find_ie(WLAN_EID_MESH_CONFIG,
 216                      a->information_elements,
 217                      a->len_information_elements);
 218         if (!ie)
 219                 return false;
 220         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 221                 return false;
 222
 223         /*
 224          * Ignore mesh capability (last two bytes of the IE) when
 225          * comparing since that may differ between stations taking
 226          * part in the same mesh.
 227          */
 228         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 229 }
 230
 231 static int cmp_bss(struct cfg80211_bss *a,
 232                    struct cfg80211_bss *b)
 233 {
 234         int r;
 235
 236         if (a->channel != b->channel)
 237                 return b->channel->center_freq - a->channel->center_freq;
 238
 239         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 240         if (r)
 241                 return r;
 242
 243         if (is_zero_ether_addr(a->bssid)) {
 244                 r = cmp_ies(WLAN_EID_MESH_ID,
 245                             a->information_elements,
 246                             a->len_information_elements,
 247                             b->information_elements,
 248                             b->len_information_elements);
 249                 if (r)
 250                         return r;
 251                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 252                                a->information_elements,
 253                                a->len_information_elements,
 254                                b->information_elements,
 255                                b->len_information_elements);
 256         }
 257
 258         return cmp_ies(WLAN_EID_SSID,
 259                        a->information_elements,
 260                        a->len_information_elements,
 261                        b->information_elements,
 262                        b->len_information_elements);
 263 }
 264
 265 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 266                                       struct ieee80211_channel *channel,
 267                                       const u8 *bssid,
 268                                       const u8 *ssid, size_t ssid_len,
 269                                       u16 capa_mask, u16 capa_val)
 270 {
 271         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 272         struct cfg80211_internal_bss *bss, *res = NULL;
 273
 274         spin_lock_bh(&dev->bss_lock);
 275
 276         list_for_each_entry(bss, &dev->bss_list, list) {
 277                 if ((bss->pub.capability & capa_mask) != capa_val)
 278                         continue;
 279                 if (channel && bss->pub.channel != channel)
 280                         continue;
 281                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 282                         res = bss;
 283                         kref_get(&res->ref);
 284                         break;
 285                 }
 286         }
 287
 288         spin_unlock_bh(&dev->bss_lock);
 289         if (!res)
 290                 return NULL;
 291         return &res->pub;
 292 }
 293 EXPORT_SYMBOL(cfg80211_get_bss);
 294
 295 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 296                                        struct ieee80211_channel *channel,
 297                                        const u8 *meshid, size_t meshidlen,
 298                                        const u8 *meshcfg)
 299 {
 300         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 301         struct cfg80211_internal_bss *bss, *res = NULL;
 302
 303         spin_lock_bh(&dev->bss_lock);
 304
 305         list_for_each_entry(bss, &dev->bss_list, list) {
 306                 if (channel && bss->pub.channel != channel)
 307                         continue;
 308                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 309                         res = bss;
 310                         kref_get(&res->ref);
 311                         break;
 312                 }
 313         }
 314
 315         spin_unlock_bh(&dev->bss_lock);
 316         if (!res)
 317                 return NULL;
 318         return &res->pub;
 319 }
 320 EXPORT_SYMBOL(cfg80211_get_mesh);
 321
 322
 323 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 324                           struct cfg80211_internal_bss *bss)
 325 {
 326         struct rb_node **p = &dev->bss_tree.rb_node;
 327         struct rb_node *parent = NULL;
 328         struct cfg80211_internal_bss *tbss;
 329         int cmp;
 330
 331         while (*p) {
 332                 parent = *p;
 333                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 334
 335                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 336
 337                 if (WARN_ON(!cmp)) {
 338                         /* will sort of leak this BSS */
 339                         return;
 340                 }
 341
 342                 if (cmp < 0)
 343                         p = &(*p)->rb_left;
 344                 else
 345                         p = &(*p)->rb_right;
 346         }
 347
 348         rb_link_node(&bss->rbn, parent, p);
 349         rb_insert_color(&bss->rbn, &dev->bss_tree);
 350 }
 351
 352 static struct cfg80211_internal_bss *
 353 rb_find_bss(struct cfg80211_registered_device *dev,
 354             struct cfg80211_internal_bss *res)
 355 {
 356         struct rb_node *n = dev->bss_tree.rb_node;
 357         struct cfg80211_internal_bss *bss;
 358         int r;
 359
 360         while (n) {
 361                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 362                 r = cmp_bss(&res->pub, &bss->pub);
 363
 364                 if (r == 0)
 365                         return bss;
 366                 else if (r < 0)
 367                         n = n->rb_left;
 368                 else
 369                         n = n->rb_right;
 370         }
 371
 372         return NULL;
 373 }
 374
 375 static struct cfg80211_internal_bss *
 376 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 377                     struct cfg80211_internal_bss *res,
 378                     bool overwrite)
 379 {
 380         struct cfg80211_internal_bss *found = NULL;
 381         const u8 *meshid, *meshcfg;
 382
 383         /*
 384          * The reference to "res" is donated to this function.
 385          */
 386
 387         if (WARN_ON(!res->pub.channel)) {
 388                 kref_put(&res->ref, bss_release);
 389                 return NULL;
 390         }
 391
 392         res->ts = jiffies;
 393
 394         if (is_zero_ether_addr(res->pub.bssid)) {
 395                 /* must be mesh, verify */
 396                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 397                                  res->pub.len_information_elements);
 398                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 399                                   res->pub.information_elements,
 400                                   res->pub.len_information_elements);
 401                 if (!meshid || !meshcfg ||
 402                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 403                         /* bogus mesh */
 404                         kref_put(&res->ref, bss_release);
 405                         return NULL;
 406                 }
 407         }
 408
 409         spin_lock_bh(&dev->bss_lock);
 410
 411         found = rb_find_bss(dev, res);
 412
 413         if (found) {
 414                 found->pub.beacon_interval = res->pub.beacon_interval;
 415                 found->pub.tsf = res->pub.tsf;
 416                 found->pub.signal = res->pub.signal;
 417                 found->pub.capability = res->pub.capability;
 418                 found->ts = res->ts;
 419
 420                 /* overwrite IEs */
 421                 if (overwrite) {
 422                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 423                         size_t ielen = res->pub.len_information_elements;
 424
 425                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 426                                 memcpy(found->pub.information_elements,
 427                                        res->pub.information_elements, ielen);
 428                                 found->pub.len_information_elements = ielen;
 429                         } else {
 430                                 u8 *ies = found->pub.information_elements;
 431
 432                                 if (found->ies_allocated)
 433                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 434                                 else
 435                                         ies = kmalloc(ielen, GFP_ATOMIC);
 436
 437                                 if (ies) {
 438                                         memcpy(ies, res->pub.information_elements, ielen);
 439                                         found->ies_allocated = true;
 440                                         found->pub.information_elements = ies;
 441                                         found->pub.len_information_elements = ielen;
 442                                 }
 443                         }
 444                 }
 445
 446                 kref_put(&res->ref, bss_release);
 447         } else {
 448                 /* this "consumes" the reference */
 449                 list_add_tail(&res->list, &dev->bss_list);
 450                 rb_insert_bss(dev, res);
 451                 found = res;
 452         }
 453
 454         dev->bss_generation++;
 455         spin_unlock_bh(&dev->bss_lock);
 456
 457         kref_get(&found->ref);
 458         return found;
 459 }
 460
 461 struct cfg80211_bss*
 462 cfg80211_inform_bss(struct wiphy *wiphy,
 463                     struct ieee80211_channel *channel,
 464                     const u8 *bssid,
 465                     u64 timestamp, u16 capability, u16 beacon_interval,
 466                     const u8 *ie, size_t ielen,
 467                     s32 signal, gfp_t gfp)
 468 {
 469         struct cfg80211_internal_bss *res;
 470         size_t privsz;
 471
 472         if (WARN_ON(!wiphy))
 473                 return NULL;
 474
 475         privsz = wiphy->bss_priv_size;
 476
 477         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 478                         (signal < 0 || signal > 100)))
 479                 return NULL;
 480
 481         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 482         if (!res)
 483                 return NULL;
 484
 485         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 486         res->pub.channel = channel;
 487         res->pub.signal = signal;
 488         res->pub.tsf = timestamp;
 489         res->pub.beacon_interval = beacon_interval;
 490         res->pub.capability = capability;
 491         /* point to after the private area */
 492         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 493         memcpy(res->pub.information_elements, ie, ielen);
 494         res->pub.len_information_elements = ielen;
 495
 496         kref_init(&res->ref);
 497
 498         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 499         if (!res)
 500                 return NULL;
 501
 502         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 503                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 504
 505         /* cfg80211_bss_update gives us a referenced result */
 506         return &res->pub;
 507 }
 508 EXPORT_SYMBOL(cfg80211_inform_bss);
 509
 510 struct cfg80211_bss *
 511 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 512                           struct ieee80211_channel *channel,
 513                           struct ieee80211_mgmt *mgmt, size_t len,
 514                           s32 signal, gfp_t gfp)
 515 {
 516         struct cfg80211_internal_bss *res;
 517         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 518                                       u.probe_resp.variable);
 519         bool overwrite;
 520         size_t privsz = wiphy->bss_priv_size;
 521
 522         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 523                     (signal < 0 || signal > 100)))
 524                 return NULL;
 525
 526         if (WARN_ON(!mgmt || !wiphy ||
 527                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 528                 return NULL;
 529
 530         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 531         if (!res)
 532                 return NULL;
 533
 534         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 535         res->pub.channel = channel;
 536         res->pub.signal = signal;
 537         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 538         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 539         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 540         /* point to after the private area */
 541         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 542         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 543         res->pub.len_information_elements = ielen;
 544
 545         kref_init(&res->ref);
 546
 547         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 548
 549         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 550         if (!res)
 551                 return NULL;
 552
 553         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 554                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 555
 556         /* cfg80211_bss_update gives us a referenced result */
 557         return &res->pub;
 558 }
 559 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 560
 561 void cfg80211_put_bss(struct cfg80211_bss *pub)
 562 {
 563         struct cfg80211_internal_bss *bss;
 564
 565         if (!pub)
 566                 return;
 567
 568         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 569         kref_put(&bss->ref, bss_release);
 570 }
 571 EXPORT_SYMBOL(cfg80211_put_bss);
 572
 573 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 574 {
 575         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 576         struct cfg80211_internal_bss *bss;
 577
 578         if (WARN_ON(!pub))
 579                 return;
 580
 581         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 582
 583         spin_lock_bh(&dev->bss_lock);
 584
 585         list_del(&bss->list);
 586         dev->bss_generation++;
 587         rb_erase(&bss->rbn, &dev->bss_tree);
 588
 589         spin_unlock_bh(&dev->bss_lock);
 590
 591         kref_put(&bss->ref, bss_release);
 592 }
 593 EXPORT_SYMBOL(cfg80211_unlink_bss);
 594
 595 #ifdef CONFIG_WIRELESS_EXT
 596 int cfg80211_wext_siwscan(struct net_device *dev,
 597                           struct iw_request_info *info,
 598                           union iwreq_data *wrqu, char *extra)
 599 {
 600         struct cfg80211_registered_device *rdev;
 601         struct wiphy *wiphy;
 602         struct iw_scan_req *wreq = NULL;
 603         struct cfg80211_scan_request *creq;
 604         int i, err, n_channels = 0;
 605         enum ieee80211_band band;
 606
 607         if (!netif_running(dev))
 608                 return -ENETDOWN;
 609
 610         if (wrqu->data.length == sizeof(struct iw_scan_req))
 611                 wreq = (struct iw_scan_req *)extra;
 612
 613         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 614
 615         if (IS_ERR(rdev))
 616                 return PTR_ERR(rdev);
 617
 618         if (rdev->scan_req) {
 619                 err = -EBUSY;
 620                 goto out;
 621         }
 622
 623         wiphy = &rdev->wiphy;
 624
 625         /* Determine number of channels, needed to allocate creq */
 626         if (wreq && wreq->num_channels)
 627                 n_channels = wreq->num_channels;
 628         else {
 629                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 630                         if (wiphy->bands[band])
 631                                 n_channels += wiphy->bands[band]->n_channels;
 632         }
 633
 634         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 635                        n_channels * sizeof(void *),
 636                        GFP_ATOMIC);
 637         if (!creq) {
 638                 err = -ENOMEM;
 639                 goto out;
 640         }
 641
 642         creq->wiphy = wiphy;
 643         creq->dev = dev;
 644         /* SSIDs come after channels */
 645         creq->ssids = (void *)&creq->channels[n_channels];
 646         creq->n_channels = n_channels;
 647         creq->n_ssids = 1;
 648
 649         /* translate "Scan on frequencies" request */
 650         i = 0;
 651         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 652                 int j;
 653                 if (!wiphy->bands[band])
 654                         continue;
 655                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 656
 657                         /* If we have a wireless request structure and the
 658                          * wireless request specifies frequencies, then search
 659                          * for the matching hardware channel.
 660                          */
 661                         if (wreq && wreq->num_channels) {
 662                                 int k;
 663                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 664                                 for (k = 0; k < wreq->num_channels; k++) {
 665                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 666                                         if (wext_freq == wiphy_freq)
 667                                                 goto wext_freq_found;
 668                                 }
 669                                 goto wext_freq_not_found;
 670                         }
 671
 672                 wext_freq_found:
 673                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 674                         i++;
 675                 wext_freq_not_found: ;
 676                 }
 677         }
 678         /* No channels found? */
 679         if (!i) {
 680                 err = -EINVAL;
 681                 goto out;
 682         }
 683
 684         /* Set real number of channels specified in creq->channels[] */
 685         creq->n_channels = i;
 686
 687         /* translate "Scan for SSID" request */
 688         if (wreq) {
 689                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 690                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 691                                 return -EINVAL;
 692                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 693                         creq->ssids[0].ssid_len = wreq->essid_len;
 694                 }
 695                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 696                         creq->n_ssids = 0;
 697         }
 698
 699         rdev->scan_req = creq;
 700         err = rdev->ops->scan(wiphy, dev, creq);
 701         if (err) {
 702                 rdev->scan_req = NULL;
 703                 kfree(creq);
 704         } else {
 705                 nl80211_send_scan_start(rdev, dev);
 706                 dev_hold(dev);
 707         }
 708  out:
 709         cfg80211_unlock_rdev(rdev);
 710         return err;
 711 }
 712 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 713
 714 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 715                                    struct cfg80211_bss *bss,
 716                                    char **current_ev, char *end_buf)
 717 {
 718         u8 *pos, *end, *next;
 719         struct iw_event iwe;
 720
 721         if (!bss->information_elements ||
 722             !bss->len_information_elements)
 723                 return;
 724
 725         /*
 726          * If needed, fragment the IEs buffer (at IE boundaries) into short
 727          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 728          */
 729         pos = bss->information_elements;
 730         end = pos + bss->len_information_elements;
 731
 732         while (end - pos > IW_GENERIC_IE_MAX) {
 733                 next = pos + 2 + pos[1];
 734                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 735                         next = next + 2 + next[1];
 736
 737                 memset(&iwe, 0, sizeof(iwe));
 738                 iwe.cmd = IWEVGENIE;
 739                 iwe.u.data.length = next - pos;
 740                 *current_ev = iwe_stream_add_point(info, *current_ev,
 741                                                    end_buf, &iwe, pos);
 742
 743                 pos = next;
 744         }
 745
 746         if (end > pos) {
 747                 memset(&iwe, 0, sizeof(iwe));
 748                 iwe.cmd = IWEVGENIE;
 749                 iwe.u.data.length = end - pos;
 750                 *current_ev = iwe_stream_add_point(info, *current_ev,
 751                                                    end_buf, &iwe, pos);
 752         }
 753 }
 754
 755 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 756 {
 757         unsigned long end = jiffies;
 758
 759         if (end >= start)
 760                 return jiffies_to_msecs(end - start);
 761
 762         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 763 }
 764
 765 static char *
 766 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 767               struct cfg80211_internal_bss *bss, char *current_ev,
 768               char *end_buf)
 769 {
 770         struct iw_event iwe;
 771         u8 *buf, *cfg, *p;
 772         u8 *ie = bss->pub.information_elements;
 773         int rem = bss->pub.len_information_elements, i, sig;
 774         bool ismesh = false;
 775
 776         memset(&iwe, 0, sizeof(iwe));
 777         iwe.cmd = SIOCGIWAP;
 778         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 779         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 780         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 781                                           IW_EV_ADDR_LEN);
 782
 783         memset(&iwe, 0, sizeof(iwe));
 784         iwe.cmd = SIOCGIWFREQ;
 785         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 786         iwe.u.freq.e = 0;
 787         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 788                                           IW_EV_FREQ_LEN);
 789
 790         memset(&iwe, 0, sizeof(iwe));
 791         iwe.cmd = SIOCGIWFREQ;
 792         iwe.u.freq.m = bss->pub.channel->center_freq;
 793         iwe.u.freq.e = 6;
 794         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 795                                           IW_EV_FREQ_LEN);
 796
 797         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 798                 memset(&iwe, 0, sizeof(iwe));
 799                 iwe.cmd = IWEVQUAL;
 800                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 801                                      IW_QUAL_NOISE_INVALID |
 802                                      IW_QUAL_QUAL_UPDATED;
 803                 switch (wiphy->signal_type) {
 804                 case CFG80211_SIGNAL_TYPE_MBM:
 805                         sig = bss->pub.signal / 100;
 806                         iwe.u.qual.level = sig;
 807                         iwe.u.qual.updated |= IW_QUAL_DBM;
 808                         if (sig < -110)         /* rather bad */
 809                                 sig = -110;
 810                         else if (sig > -40)     /* perfect */
 811                                 sig = -40;
 812                         /* will give a range of 0 .. 70 */
 813                         iwe.u.qual.qual = sig + 110;
 814                         break;
 815                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 816                         iwe.u.qual.level = bss->pub.signal;
 817                         /* will give range 0 .. 100 */
 818                         iwe.u.qual.qual = bss->pub.signal;
 819                         break;
 820                 default:
 821                         /* not reached */
 822                         break;
 823                 }
 824                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 825                                                   &iwe, IW_EV_QUAL_LEN);
 826         }
 827
 828         memset(&iwe, 0, sizeof(iwe));
 829         iwe.cmd = SIOCGIWENCODE;
 830         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 831                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 832         else
 833                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 834         iwe.u.data.length = 0;
 835         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 836                                           &iwe, "");
 837
 838         while (rem >= 2) {
 839                 /* invalid data */
 840                 if (ie[1] > rem - 2)
 841                         break;
 842
 843                 switch (ie[0]) {
 844                 case WLAN_EID_SSID:
 845                         memset(&iwe, 0, sizeof(iwe));
 846                         iwe.cmd = SIOCGIWESSID;
 847                         iwe.u.data.length = ie[1];
 848                         iwe.u.data.flags = 1;
 849                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 850                                                           &iwe, ie + 2);
 851                         break;
 852                 case WLAN_EID_MESH_ID:
 853                         memset(&iwe, 0, sizeof(iwe));
 854                         iwe.cmd = SIOCGIWESSID;
 855                         iwe.u.data.length = ie[1];
 856                         iwe.u.data.flags = 1;
 857                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 858                                                           &iwe, ie + 2);
 859                         break;
 860                 case WLAN_EID_MESH_CONFIG:
 861                         ismesh = true;
 862                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 863                                 break;
 864                         buf = kmalloc(50, GFP_ATOMIC);
 865                         if (!buf)
 866                                 break;
 867                         cfg = ie + 2;
 868                         memset(&iwe, 0, sizeof(iwe));
 869                         iwe.cmd = IWEVCUSTOM;
 870                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 871                         iwe.u.data.length = strlen(buf);
 872                         current_ev = iwe_stream_add_point(info, current_ev,
 873                                                           end_buf,
 874                                                           &iwe, buf);
 875                         sprintf(buf, "Path Selection Protocol ID: "
 876                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 877                                                         cfg[4]);
 878                         iwe.u.data.length = strlen(buf);
 879                         current_ev = iwe_stream_add_point(info, current_ev,
 880                                                           end_buf,
 881                                                           &iwe, buf);
 882                         sprintf(buf, "Path Selection Metric ID: "
 883                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 884                                                         cfg[8]);
 885                         iwe.u.data.length = strlen(buf);
 886                         current_ev = iwe_stream_add_point(info, current_ev,
 887                                                           end_buf,
 888                                                           &iwe, buf);
 889                         sprintf(buf, "Congestion Control Mode ID: "
 890                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 891                                                         cfg[11], cfg[12]);
 892                         iwe.u.data.length = strlen(buf);
 893                         current_ev = iwe_stream_add_point(info, current_ev,
 894                                                           end_buf,
 895                                                           &iwe, buf);
 896                         sprintf(buf, "Channel Precedence: "
 897                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 898                                                         cfg[15], cfg[16]);
 899                         iwe.u.data.length = strlen(buf);
 900                         current_ev = iwe_stream_add_point(info, current_ev,
 901                                                           end_buf,
 902                                                           &iwe, buf);
 903                         kfree(buf);
 904                         break;
 905                 case WLAN_EID_SUPP_RATES:
 906                 case WLAN_EID_EXT_SUPP_RATES:
 907                         /* display all supported rates in readable format */
 908                         p = current_ev + iwe_stream_lcp_len(info);
 909
 910                         memset(&iwe, 0, sizeof(iwe));
 911                         iwe.cmd = SIOCGIWRATE;
 912                         /* Those two flags are ignored... */
 913                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 914
 915                         for (i = 0; i < ie[1]; i++) {
 916                                 iwe.u.bitrate.value =
 917                                         ((ie[i + 2] & 0x7f) * 500000);
 918                                 p = iwe_stream_add_value(info, current_ev, p,
 919                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 920                         }
 921                         current_ev = p;
 922                         break;
 923                 }
 924                 rem -= ie[1] + 2;
 925                 ie += ie[1] + 2;
 926         }
 927
 928         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 929             || ismesh) {
 930                 memset(&iwe, 0, sizeof(iwe));
 931                 iwe.cmd = SIOCGIWMODE;
 932                 if (ismesh)
 933                         iwe.u.mode = IW_MODE_MESH;
 934                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 935                         iwe.u.mode = IW_MODE_MASTER;
 936                 else
 937                         iwe.u.mode = IW_MODE_ADHOC;
 938                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 939                                                   &iwe, IW_EV_UINT_LEN);
 940         }
 941
 942         buf = kmalloc(30, GFP_ATOMIC);
 943         if (buf) {
 944                 memset(&iwe, 0, sizeof(iwe));
 945                 iwe.cmd = IWEVCUSTOM;
 946                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 947                 iwe.u.data.length = strlen(buf);
 948                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 949                                                   &iwe, buf);
 950                 memset(&iwe, 0, sizeof(iwe));
 951                 iwe.cmd = IWEVCUSTOM;
 952                 sprintf(buf, " Last beacon: %ums ago",
 953                         elapsed_jiffies_msecs(bss->ts));
 954                 iwe.u.data.length = strlen(buf);
 955                 current_ev = iwe_stream_add_point(info, current_ev,
 956                                                   end_buf, &iwe, buf);
 957                 kfree(buf);
 958         }
 959
 960         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 961
 962         return current_ev;
 963 }
 964
 965
 966 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 967                                   struct iw_request_info *info,
 968                                   char *buf, size_t len)
 969 {
 970         char *current_ev = buf;
 971         char *end_buf = buf + len;
 972         struct cfg80211_internal_bss *bss;
 973
 974         spin_lock_bh(&dev->bss_lock);
 975         cfg80211_bss_expire(dev);
 976
 977         list_for_each_entry(bss, &dev->bss_list, list) {
 978                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 979                         spin_unlock_bh(&dev->bss_lock);
 980                         return -E2BIG;
 981                 }
 982                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 983                                            current_ev, end_buf);
 984         }
 985         spin_unlock_bh(&dev->bss_lock);
 986         return current_ev - buf;
 987 }
 988
 989
 990 int cfg80211_wext_giwscan(struct net_device *dev,
 991                           struct iw_request_info *info,
 992                           struct iw_point *data, char *extra)
 993 {
 994         struct cfg80211_registered_device *rdev;
 995         int res;
 996
 997         if (!netif_running(dev))
 998                 return -ENETDOWN;
 999
1000         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1001
1002         if (IS_ERR(rdev))
1003                 return PTR_ERR(rdev);
1004
1005         if (rdev->scan_req) {
1006                 res = -EAGAIN;
1007                 goto out;
1008         }
1009
1010         res = ieee80211_scan_results(rdev, info, extra, data->length);
1011         data->length = 0;
1012         if (res >= 0) {
1013                 data->length = res;
1014                 res = 0;
1015         }
1016
1017  out:
1018         cfg80211_unlock_rdev(rdev);
1019         return res;
1020 }
1021 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1022 #endif