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
  18 #define IEEE80211_SCAN_RESULT_EXPIRE    (10 * HZ)
  19
  20 void __cfg80211_scan_done(struct work_struct *wk)
  21 {
  22         struct cfg80211_registered_device *rdev;
  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         rdev = container_of(wk, struct cfg80211_registered_device,
  30                             scan_done_wk);
  31
  32         mutex_lock(&rdev->mtx);
  33         request = rdev->scan_req;
  34
  35         dev = dev_get_by_index(&init_net, request->ifidx);
  36         if (!dev)
  37                 goto out;
  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(wiphy_to_dev(request->wiphy), dev);
  48         else
  49                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  50
  51 #ifdef CONFIG_WIRELESS_EXT
  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  out:
  62         cfg80211_unlock_rdev(rdev);
  63         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  64         kfree(request);
  65 }
  66
  67 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  68 {
  69         struct net_device *dev = dev_get_by_index(&init_net, request->ifidx);
  70         if (WARN_ON(!dev)) {
  71                 kfree(request);
  72                 return;
  73         }
  74
  75         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  76
  77         request->aborted = aborted;
  78         schedule_work(&wiphy_to_dev(request->wiphy)->scan_done_wk);
  79         dev_put(dev);
  80 }
  81 EXPORT_SYMBOL(cfg80211_scan_done);
  82
  83 static void bss_release(struct kref *ref)
  84 {
  85         struct cfg80211_internal_bss *bss;
  86
  87         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  88         if (bss->pub.free_priv)
  89                 bss->pub.free_priv(&bss->pub);
  90
  91         if (bss->ies_allocated)
  92                 kfree(bss->pub.information_elements);
  93
  94         BUG_ON(atomic_read(&bss->hold));
  95
  96         kfree(bss);
  97 }
  98
  99 /* must hold dev->bss_lock! */
 100 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 101                       unsigned long age_secs)
 102 {
 103         struct cfg80211_internal_bss *bss;
 104         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 105
 106         list_for_each_entry(bss, &dev->bss_list, list) {
 107                 bss->ts -= age_jiffies;
 108         }
 109 }
 110
 111 /* must hold dev->bss_lock! */
 112 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 113 {
 114         struct cfg80211_internal_bss *bss, *tmp;
 115         bool expired = false;
 116
 117         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 118                 if (atomic_read(&bss->hold))
 119                         continue;
 120                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 121                         continue;
 122                 list_del(&bss->list);
 123                 rb_erase(&bss->rbn, &dev->bss_tree);
 124                 kref_put(&bss->ref, bss_release);
 125                 expired = true;
 126         }
 127
 128         if (expired)
 129                 dev->bss_generation++;
 130 }
 131
 132 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 133 {
 134         while (len > 2 && ies[0] != num) {
 135                 len -= ies[1] + 2;
 136                 ies += ies[1] + 2;
 137         }
 138         if (len < 2)
 139                 return NULL;
 140         if (len < 2 + ies[1])
 141                 return NULL;
 142         return ies;
 143 }
 144
 145 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 146 {
 147         const u8 *ie1 = find_ie(num, ies1, len1);
 148         const u8 *ie2 = find_ie(num, ies2, len2);
 149         int r;
 150
 151         if (!ie1 && !ie2)
 152                 return 0;
 153         if (!ie1)
 154                 return -1;
 155
 156         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 157         if (r == 0 && ie1[1] != ie2[1])
 158                 return ie2[1] - ie1[1];
 159         return r;
 160 }
 161
 162 static bool is_bss(struct cfg80211_bss *a,
 163                    const u8 *bssid,
 164                    const u8 *ssid, size_t ssid_len)
 165 {
 166         const u8 *ssidie;
 167
 168         if (bssid && compare_ether_addr(a->bssid, bssid))
 169                 return false;
 170
 171         if (!ssid)
 172                 return true;
 173
 174         ssidie = find_ie(WLAN_EID_SSID,
 175                          a->information_elements,
 176                          a->len_information_elements);
 177         if (!ssidie)
 178                 return false;
 179         if (ssidie[1] != ssid_len)
 180                 return false;
 181         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 182 }
 183
 184 static bool is_mesh(struct cfg80211_bss *a,
 185                     const u8 *meshid, size_t meshidlen,
 186                     const u8 *meshcfg)
 187 {
 188         const u8 *ie;
 189
 190         if (!is_zero_ether_addr(a->bssid))
 191                 return false;
 192
 193         ie = find_ie(WLAN_EID_MESH_ID,
 194                      a->information_elements,
 195                      a->len_information_elements);
 196         if (!ie)
 197                 return false;
 198         if (ie[1] != meshidlen)
 199                 return false;
 200         if (memcmp(ie + 2, meshid, meshidlen))
 201                 return false;
 202
 203         ie = find_ie(WLAN_EID_MESH_CONFIG,
 204                      a->information_elements,
 205                      a->len_information_elements);
 206         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 207                 return false;
 208
 209         /*
 210          * Ignore mesh capability (last two bytes of the IE) when
 211          * comparing since that may differ between stations taking
 212          * part in the same mesh.
 213          */
 214         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 215 }
 216
 217 static int cmp_bss(struct cfg80211_bss *a,
 218                    struct cfg80211_bss *b)
 219 {
 220         int r;
 221
 222         if (a->channel != b->channel)
 223                 return b->channel->center_freq - a->channel->center_freq;
 224
 225         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 226         if (r)
 227                 return r;
 228
 229         if (is_zero_ether_addr(a->bssid)) {
 230                 r = cmp_ies(WLAN_EID_MESH_ID,
 231                             a->information_elements,
 232                             a->len_information_elements,
 233                             b->information_elements,
 234                             b->len_information_elements);
 235                 if (r)
 236                         return r;
 237                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 238                                a->information_elements,
 239                                a->len_information_elements,
 240                                b->information_elements,
 241                                b->len_information_elements);
 242         }
 243
 244         return cmp_ies(WLAN_EID_SSID,
 245                        a->information_elements,
 246                        a->len_information_elements,
 247                        b->information_elements,
 248                        b->len_information_elements);
 249 }
 250
 251 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 252                                       struct ieee80211_channel *channel,
 253                                       const u8 *bssid,
 254                                       const u8 *ssid, size_t ssid_len,
 255                                       u16 capa_mask, u16 capa_val)
 256 {
 257         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 258         struct cfg80211_internal_bss *bss, *res = NULL;
 259
 260         spin_lock_bh(&dev->bss_lock);
 261
 262         list_for_each_entry(bss, &dev->bss_list, list) {
 263                 if ((bss->pub.capability & capa_mask) != capa_val)
 264                         continue;
 265                 if (channel && bss->pub.channel != channel)
 266                         continue;
 267                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 268                         res = bss;
 269                         kref_get(&res->ref);
 270                         break;
 271                 }
 272         }
 273
 274         spin_unlock_bh(&dev->bss_lock);
 275         if (!res)
 276                 return NULL;
 277         return &res->pub;
 278 }
 279 EXPORT_SYMBOL(cfg80211_get_bss);
 280
 281 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 282                                        struct ieee80211_channel *channel,
 283                                        const u8 *meshid, size_t meshidlen,
 284                                        const u8 *meshcfg)
 285 {
 286         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 287         struct cfg80211_internal_bss *bss, *res = NULL;
 288
 289         spin_lock_bh(&dev->bss_lock);
 290
 291         list_for_each_entry(bss, &dev->bss_list, list) {
 292                 if (channel && bss->pub.channel != channel)
 293                         continue;
 294                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 295                         res = bss;
 296                         kref_get(&res->ref);
 297                         break;
 298                 }
 299         }
 300
 301         spin_unlock_bh(&dev->bss_lock);
 302         if (!res)
 303                 return NULL;
 304         return &res->pub;
 305 }
 306 EXPORT_SYMBOL(cfg80211_get_mesh);
 307
 308
 309 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 310                           struct cfg80211_internal_bss *bss)
 311 {
 312         struct rb_node **p = &dev->bss_tree.rb_node;
 313         struct rb_node *parent = NULL;
 314         struct cfg80211_internal_bss *tbss;
 315         int cmp;
 316
 317         while (*p) {
 318                 parent = *p;
 319                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 320
 321                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 322
 323                 if (WARN_ON(!cmp)) {
 324                         /* will sort of leak this BSS */
 325                         return;
 326                 }
 327
 328                 if (cmp < 0)
 329                         p = &(*p)->rb_left;
 330                 else
 331                         p = &(*p)->rb_right;
 332         }
 333
 334         rb_link_node(&bss->rbn, parent, p);
 335         rb_insert_color(&bss->rbn, &dev->bss_tree);
 336 }
 337
 338 static struct cfg80211_internal_bss *
 339 rb_find_bss(struct cfg80211_registered_device *dev,
 340             struct cfg80211_internal_bss *res)
 341 {
 342         struct rb_node *n = dev->bss_tree.rb_node;
 343         struct cfg80211_internal_bss *bss;
 344         int r;
 345
 346         while (n) {
 347                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 348                 r = cmp_bss(&res->pub, &bss->pub);
 349
 350                 if (r == 0)
 351                         return bss;
 352                 else if (r < 0)
 353                         n = n->rb_left;
 354                 else
 355                         n = n->rb_right;
 356         }
 357
 358         return NULL;
 359 }
 360
 361 static struct cfg80211_internal_bss *
 362 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 363                     struct cfg80211_internal_bss *res,
 364                     bool overwrite)
 365 {
 366         struct cfg80211_internal_bss *found = NULL;
 367         const u8 *meshid, *meshcfg;
 368
 369         /*
 370          * The reference to "res" is donated to this function.
 371          */
 372
 373         if (WARN_ON(!res->pub.channel)) {
 374                 kref_put(&res->ref, bss_release);
 375                 return NULL;
 376         }
 377
 378         res->ts = jiffies;
 379
 380         if (is_zero_ether_addr(res->pub.bssid)) {
 381                 /* must be mesh, verify */
 382                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 383                                  res->pub.len_information_elements);
 384                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 385                                   res->pub.information_elements,
 386                                   res->pub.len_information_elements);
 387                 if (!meshid || !meshcfg ||
 388                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 389                         /* bogus mesh */
 390                         kref_put(&res->ref, bss_release);
 391                         return NULL;
 392                 }
 393         }
 394
 395         spin_lock_bh(&dev->bss_lock);
 396
 397         found = rb_find_bss(dev, res);
 398
 399         if (found) {
 400                 found->pub.beacon_interval = res->pub.beacon_interval;
 401                 found->pub.tsf = res->pub.tsf;
 402                 found->pub.signal = res->pub.signal;
 403                 found->pub.capability = res->pub.capability;
 404                 found->ts = res->ts;
 405
 406                 /* overwrite IEs */
 407                 if (overwrite) {
 408                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 409                         size_t ielen = res->pub.len_information_elements;
 410
 411                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 412                                 memcpy(found->pub.information_elements,
 413                                        res->pub.information_elements, ielen);
 414                                 found->pub.len_information_elements = ielen;
 415                         } else {
 416                                 u8 *ies = found->pub.information_elements;
 417
 418                                 if (found->ies_allocated)
 419                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 420                                 else
 421                                         ies = kmalloc(ielen, GFP_ATOMIC);
 422
 423                                 if (ies) {
 424                                         memcpy(ies, res->pub.information_elements, ielen);
 425                                         found->ies_allocated = true;
 426                                         found->pub.information_elements = ies;
 427                                         found->pub.len_information_elements = ielen;
 428                                 }
 429                         }
 430                 }
 431
 432                 kref_put(&res->ref, bss_release);
 433         } else {
 434                 /* this "consumes" the reference */
 435                 list_add_tail(&res->list, &dev->bss_list);
 436                 rb_insert_bss(dev, res);
 437                 found = res;
 438         }
 439
 440         dev->bss_generation++;
 441         spin_unlock_bh(&dev->bss_lock);
 442
 443         kref_get(&found->ref);
 444         return found;
 445 }
 446
 447 struct cfg80211_bss*
 448 cfg80211_inform_bss(struct wiphy *wiphy,
 449                     struct ieee80211_channel *channel,
 450                     const u8 *bssid,
 451                     u64 timestamp, u16 capability, u16 beacon_interval,
 452                     const u8 *ie, size_t ielen,
 453                     s32 signal, gfp_t gfp)
 454 {
 455         struct cfg80211_internal_bss *res;
 456         size_t privsz;
 457
 458         if (WARN_ON(!wiphy))
 459                 return NULL;
 460
 461         privsz = wiphy->bss_priv_size;
 462
 463         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 464                         (signal < 0 || signal > 100)))
 465                 return NULL;
 466
 467         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 468         if (!res)
 469                 return NULL;
 470
 471         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 472         res->pub.channel = channel;
 473         res->pub.signal = signal;
 474         res->pub.tsf = timestamp;
 475         res->pub.beacon_interval = beacon_interval;
 476         res->pub.capability = capability;
 477         /* point to after the private area */
 478         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 479         memcpy(res->pub.information_elements, ie, ielen);
 480         res->pub.len_information_elements = ielen;
 481
 482         kref_init(&res->ref);
 483
 484         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 485         if (!res)
 486                 return NULL;
 487
 488         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 489                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 490
 491         /* cfg80211_bss_update gives us a referenced result */
 492         return &res->pub;
 493 }
 494 EXPORT_SYMBOL(cfg80211_inform_bss);
 495
 496 struct cfg80211_bss *
 497 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 498                           struct ieee80211_channel *channel,
 499                           struct ieee80211_mgmt *mgmt, size_t len,
 500                           s32 signal, gfp_t gfp)
 501 {
 502         struct cfg80211_internal_bss *res;
 503         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 504                                       u.probe_resp.variable);
 505         bool overwrite;
 506         size_t privsz = wiphy->bss_priv_size;
 507
 508         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 509                     (signal < 0 || signal > 100)))
 510                 return NULL;
 511
 512         if (WARN_ON(!mgmt || !wiphy ||
 513                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 514                 return NULL;
 515
 516         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 517         if (!res)
 518                 return NULL;
 519
 520         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 521         res->pub.channel = channel;
 522         res->pub.signal = signal;
 523         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 524         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 525         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 526         /* point to after the private area */
 527         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 528         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 529         res->pub.len_information_elements = ielen;
 530
 531         kref_init(&res->ref);
 532
 533         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 534
 535         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 536         if (!res)
 537                 return NULL;
 538
 539         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 540                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 541
 542         /* cfg80211_bss_update gives us a referenced result */
 543         return &res->pub;
 544 }
 545 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 546
 547 void cfg80211_put_bss(struct cfg80211_bss *pub)
 548 {
 549         struct cfg80211_internal_bss *bss;
 550
 551         if (!pub)
 552                 return;
 553
 554         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 555         kref_put(&bss->ref, bss_release);
 556 }
 557 EXPORT_SYMBOL(cfg80211_put_bss);
 558
 559 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 560 {
 561         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 562         struct cfg80211_internal_bss *bss;
 563
 564         if (WARN_ON(!pub))
 565                 return;
 566
 567         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 568
 569         spin_lock_bh(&dev->bss_lock);
 570
 571         list_del(&bss->list);
 572         rb_erase(&bss->rbn, &dev->bss_tree);
 573
 574         spin_unlock_bh(&dev->bss_lock);
 575
 576         kref_put(&bss->ref, bss_release);
 577 }
 578 EXPORT_SYMBOL(cfg80211_unlink_bss);
 579
 580 #ifdef CONFIG_WIRELESS_EXT
 581 int cfg80211_wext_siwscan(struct net_device *dev,
 582                           struct iw_request_info *info,
 583                           union iwreq_data *wrqu, char *extra)
 584 {
 585         struct cfg80211_registered_device *rdev;
 586         struct wiphy *wiphy;
 587         struct iw_scan_req *wreq = NULL;
 588         struct cfg80211_scan_request *creq;
 589         int i, err, n_channels = 0;
 590         enum ieee80211_band band;
 591
 592         if (!netif_running(dev))
 593                 return -ENETDOWN;
 594
 595         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 596
 597         if (IS_ERR(rdev))
 598                 return PTR_ERR(rdev);
 599
 600         if (rdev->scan_req) {
 601                 err = -EBUSY;
 602                 goto out;
 603         }
 604
 605         wiphy = &rdev->wiphy;
 606
 607         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 608                 if (wiphy->bands[band])
 609                         n_channels += wiphy->bands[band]->n_channels;
 610
 611         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 612                        n_channels * sizeof(void *),
 613                        GFP_ATOMIC);
 614         if (!creq) {
 615                 err = -ENOMEM;
 616                 goto out;
 617         }
 618
 619         creq->wiphy = wiphy;
 620         creq->ifidx = dev->ifindex;
 621         creq->ssids = (void *)(creq + 1);
 622         creq->channels = (void *)(creq->ssids + 1);
 623         creq->n_channels = n_channels;
 624         creq->n_ssids = 1;
 625
 626         /* all channels */
 627         i = 0;
 628         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 629                 int j;
 630                 if (!wiphy->bands[band])
 631                         continue;
 632                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 633                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 634                         i++;
 635                 }
 636         }
 637
 638         /* translate scan request */
 639         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 640                 wreq = (struct iw_scan_req *)extra;
 641
 642                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 643                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 644                                 return -EINVAL;
 645                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 646                         creq->ssids[0].ssid_len = wreq->essid_len;
 647                 }
 648                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 649                         creq->n_ssids = 0;
 650         }
 651
 652         rdev->scan_req = creq;
 653         err = rdev->ops->scan(wiphy, dev, creq);
 654         if (err) {
 655                 rdev->scan_req = NULL;
 656                 kfree(creq);
 657         } else
 658                 nl80211_send_scan_start(rdev, dev);
 659  out:
 660         cfg80211_unlock_rdev(rdev);
 661         return err;
 662 }
 663 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 664
 665 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 666                                    struct cfg80211_bss *bss,
 667                                    char **current_ev, char *end_buf)
 668 {
 669         u8 *pos, *end, *next;
 670         struct iw_event iwe;
 671
 672         if (!bss->information_elements ||
 673             !bss->len_information_elements)
 674                 return;
 675
 676         /*
 677          * If needed, fragment the IEs buffer (at IE boundaries) into short
 678          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 679          */
 680         pos = bss->information_elements;
 681         end = pos + bss->len_information_elements;
 682
 683         while (end - pos > IW_GENERIC_IE_MAX) {
 684                 next = pos + 2 + pos[1];
 685                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 686                         next = next + 2 + next[1];
 687
 688                 memset(&iwe, 0, sizeof(iwe));
 689                 iwe.cmd = IWEVGENIE;
 690                 iwe.u.data.length = next - pos;
 691                 *current_ev = iwe_stream_add_point(info, *current_ev,
 692                                                    end_buf, &iwe, pos);
 693
 694                 pos = next;
 695         }
 696
 697         if (end > pos) {
 698                 memset(&iwe, 0, sizeof(iwe));
 699                 iwe.cmd = IWEVGENIE;
 700                 iwe.u.data.length = end - pos;
 701                 *current_ev = iwe_stream_add_point(info, *current_ev,
 702                                                    end_buf, &iwe, pos);
 703         }
 704 }
 705
 706 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 707 {
 708         unsigned long end = jiffies;
 709
 710         if (end >= start)
 711                 return jiffies_to_msecs(end - start);
 712
 713         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 714 }
 715
 716 static char *
 717 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 718               struct cfg80211_internal_bss *bss, char *current_ev,
 719               char *end_buf)
 720 {
 721         struct iw_event iwe;
 722         u8 *buf, *cfg, *p;
 723         u8 *ie = bss->pub.information_elements;
 724         int rem = bss->pub.len_information_elements, i, sig;
 725         bool ismesh = false;
 726
 727         memset(&iwe, 0, sizeof(iwe));
 728         iwe.cmd = SIOCGIWAP;
 729         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 730         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 731         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 732                                           IW_EV_ADDR_LEN);
 733
 734         memset(&iwe, 0, sizeof(iwe));
 735         iwe.cmd = SIOCGIWFREQ;
 736         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 737         iwe.u.freq.e = 0;
 738         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 739                                           IW_EV_FREQ_LEN);
 740
 741         memset(&iwe, 0, sizeof(iwe));
 742         iwe.cmd = SIOCGIWFREQ;
 743         iwe.u.freq.m = bss->pub.channel->center_freq;
 744         iwe.u.freq.e = 6;
 745         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 746                                           IW_EV_FREQ_LEN);
 747
 748         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 749                 memset(&iwe, 0, sizeof(iwe));
 750                 iwe.cmd = IWEVQUAL;
 751                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 752                                      IW_QUAL_NOISE_INVALID |
 753                                      IW_QUAL_QUAL_UPDATED;
 754                 switch (wiphy->signal_type) {
 755                 case CFG80211_SIGNAL_TYPE_MBM:
 756                         sig = bss->pub.signal / 100;
 757                         iwe.u.qual.level = sig;
 758                         iwe.u.qual.updated |= IW_QUAL_DBM;
 759                         if (sig < -110)         /* rather bad */
 760                                 sig = -110;
 761                         else if (sig > -40)     /* perfect */
 762                                 sig = -40;
 763                         /* will give a range of 0 .. 70 */
 764                         iwe.u.qual.qual = sig + 110;
 765                         break;
 766                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 767                         iwe.u.qual.level = bss->pub.signal;
 768                         /* will give range 0 .. 100 */
 769                         iwe.u.qual.qual = bss->pub.signal;
 770                         break;
 771                 default:
 772                         /* not reached */
 773                         break;
 774                 }
 775                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 776                                                   &iwe, IW_EV_QUAL_LEN);
 777         }
 778
 779         memset(&iwe, 0, sizeof(iwe));
 780         iwe.cmd = SIOCGIWENCODE;
 781         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 782                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 783         else
 784                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 785         iwe.u.data.length = 0;
 786         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 787                                           &iwe, "");
 788
 789         while (rem >= 2) {
 790                 /* invalid data */
 791                 if (ie[1] > rem - 2)
 792                         break;
 793
 794                 switch (ie[0]) {
 795                 case WLAN_EID_SSID:
 796                         memset(&iwe, 0, sizeof(iwe));
 797                         iwe.cmd = SIOCGIWESSID;
 798                         iwe.u.data.length = ie[1];
 799                         iwe.u.data.flags = 1;
 800                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 801                                                           &iwe, ie + 2);
 802                         break;
 803                 case WLAN_EID_MESH_ID:
 804                         memset(&iwe, 0, sizeof(iwe));
 805                         iwe.cmd = SIOCGIWESSID;
 806                         iwe.u.data.length = ie[1];
 807                         iwe.u.data.flags = 1;
 808                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 809                                                           &iwe, ie + 2);
 810                         break;
 811                 case WLAN_EID_MESH_CONFIG:
 812                         ismesh = true;
 813                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 814                                 break;
 815                         buf = kmalloc(50, GFP_ATOMIC);
 816                         if (!buf)
 817                                 break;
 818                         cfg = ie + 2;
 819                         memset(&iwe, 0, sizeof(iwe));
 820                         iwe.cmd = IWEVCUSTOM;
 821                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 822                         iwe.u.data.length = strlen(buf);
 823                         current_ev = iwe_stream_add_point(info, current_ev,
 824                                                           end_buf,
 825                                                           &iwe, buf);
 826                         sprintf(buf, "Path Selection Protocol ID: "
 827                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 828                                                         cfg[4]);
 829                         iwe.u.data.length = strlen(buf);
 830                         current_ev = iwe_stream_add_point(info, current_ev,
 831                                                           end_buf,
 832                                                           &iwe, buf);
 833                         sprintf(buf, "Path Selection Metric ID: "
 834                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 835                                                         cfg[8]);
 836                         iwe.u.data.length = strlen(buf);
 837                         current_ev = iwe_stream_add_point(info, current_ev,
 838                                                           end_buf,
 839                                                           &iwe, buf);
 840                         sprintf(buf, "Congestion Control Mode ID: "
 841                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 842                                                         cfg[11], cfg[12]);
 843                         iwe.u.data.length = strlen(buf);
 844                         current_ev = iwe_stream_add_point(info, current_ev,
 845                                                           end_buf,
 846                                                           &iwe, buf);
 847                         sprintf(buf, "Channel Precedence: "
 848                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 849                                                         cfg[15], cfg[16]);
 850                         iwe.u.data.length = strlen(buf);
 851                         current_ev = iwe_stream_add_point(info, current_ev,
 852                                                           end_buf,
 853                                                           &iwe, buf);
 854                         kfree(buf);
 855                         break;
 856                 case WLAN_EID_SUPP_RATES:
 857                 case WLAN_EID_EXT_SUPP_RATES:
 858                         /* display all supported rates in readable format */
 859                         p = current_ev + iwe_stream_lcp_len(info);
 860
 861                         memset(&iwe, 0, sizeof(iwe));
 862                         iwe.cmd = SIOCGIWRATE;
 863                         /* Those two flags are ignored... */
 864                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 865
 866                         for (i = 0; i < ie[1]; i++) {
 867                                 iwe.u.bitrate.value =
 868                                         ((ie[i + 2] & 0x7f) * 500000);
 869                                 p = iwe_stream_add_value(info, current_ev, p,
 870                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 871                         }
 872                         current_ev = p;
 873                         break;
 874                 }
 875                 rem -= ie[1] + 2;
 876                 ie += ie[1] + 2;
 877         }
 878
 879         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 880             || ismesh) {
 881                 memset(&iwe, 0, sizeof(iwe));
 882                 iwe.cmd = SIOCGIWMODE;
 883                 if (ismesh)
 884                         iwe.u.mode = IW_MODE_MESH;
 885                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 886                         iwe.u.mode = IW_MODE_MASTER;
 887                 else
 888                         iwe.u.mode = IW_MODE_ADHOC;
 889                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 890                                                   &iwe, IW_EV_UINT_LEN);
 891         }
 892
 893         buf = kmalloc(30, GFP_ATOMIC);
 894         if (buf) {
 895                 memset(&iwe, 0, sizeof(iwe));
 896                 iwe.cmd = IWEVCUSTOM;
 897                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 898                 iwe.u.data.length = strlen(buf);
 899                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 900                                                   &iwe, buf);
 901                 memset(&iwe, 0, sizeof(iwe));
 902                 iwe.cmd = IWEVCUSTOM;
 903                 sprintf(buf, " Last beacon: %ums ago",
 904                         elapsed_jiffies_msecs(bss->ts));
 905                 iwe.u.data.length = strlen(buf);
 906                 current_ev = iwe_stream_add_point(info, current_ev,
 907                                                   end_buf, &iwe, buf);
 908                 kfree(buf);
 909         }
 910
 911         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 912
 913         return current_ev;
 914 }
 915
 916
 917 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 918                                   struct iw_request_info *info,
 919                                   char *buf, size_t len)
 920 {
 921         char *current_ev = buf;
 922         char *end_buf = buf + len;
 923         struct cfg80211_internal_bss *bss;
 924
 925         spin_lock_bh(&dev->bss_lock);
 926         cfg80211_bss_expire(dev);
 927
 928         list_for_each_entry(bss, &dev->bss_list, list) {
 929                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 930                         spin_unlock_bh(&dev->bss_lock);
 931                         return -E2BIG;
 932                 }
 933                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 934                                            current_ev, end_buf);
 935         }
 936         spin_unlock_bh(&dev->bss_lock);
 937         return current_ev - buf;
 938 }
 939
 940
 941 int cfg80211_wext_giwscan(struct net_device *dev,
 942                           struct iw_request_info *info,
 943                           struct iw_point *data, char *extra)
 944 {
 945         struct cfg80211_registered_device *rdev;
 946         int res;
 947
 948         if (!netif_running(dev))
 949                 return -ENETDOWN;
 950
 951         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 952
 953         if (IS_ERR(rdev))
 954                 return PTR_ERR(rdev);
 955
 956         if (rdev->scan_req) {
 957                 res = -EAGAIN;
 958                 goto out;
 959         }
 960
 961         res = ieee80211_scan_results(rdev, info, extra, data->length);
 962         data->length = 0;
 963         if (res >= 0) {
 964                 data->length = res;
 965                 res = 0;
 966         }
 967
 968  out:
 969         cfg80211_unlock_rdev(rdev);
 970         return res;
 971 }
 972 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 973 #endif