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   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 cfg80211_scan_request *request, bool aborted)
  21 {
  22         struct net_device *dev;
  23 #ifdef CONFIG_WIRELESS_EXT
  24         union iwreq_data wrqu;
  25 #endif
  26
  27         dev = dev_get_by_index(&init_net, request->ifidx);
  28         if (!dev)
  29                 goto out;
  30
  31         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  32
  33         /*
  34          * This must be before sending the other events!
  35          * Otherwise, wpa_supplicant gets completely confused with
  36          * wext events.
  37          */
  38         cfg80211_sme_scan_done(dev);
  39
  40         if (aborted)
  41                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  42         else
  43                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  44
  45         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  46
  47 #ifdef CONFIG_WIRELESS_EXT
  48         if (!aborted) {
  49                 memset(&wrqu, 0, sizeof(wrqu));
  50
  51                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  52         }
  53 #endif
  54
  55         dev_put(dev);
  56
  57  out:
  58         kfree(request);
  59 }
  60 EXPORT_SYMBOL(cfg80211_scan_done);
  61
  62 static void bss_release(struct kref *ref)
  63 {
  64         struct cfg80211_internal_bss *bss;
  65
  66         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  67         if (bss->pub.free_priv)
  68                 bss->pub.free_priv(&bss->pub);
  69
  70         if (bss->ies_allocated)
  71                 kfree(bss->pub.information_elements);
  72
  73         kfree(bss);
  74 }
  75
  76 /* must hold dev->bss_lock! */
  77 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
  78                       unsigned long age_secs)
  79 {
  80         struct cfg80211_internal_bss *bss;
  81         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
  82
  83         list_for_each_entry(bss, &dev->bss_list, list) {
  84                 bss->ts -= age_jiffies;
  85         }
  86 }
  87
  88 /* must hold dev->bss_lock! */
  89 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
  90 {
  91         struct cfg80211_internal_bss *bss, *tmp;
  92         bool expired = false;
  93
  94         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
  95                 if (bss->hold ||
  96                     !time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
  97                         continue;
  98                 list_del(&bss->list);
  99                 rb_erase(&bss->rbn, &dev->bss_tree);
 100                 kref_put(&bss->ref, bss_release);
 101                 expired = true;
 102         }
 103
 104         if (expired)
 105                 dev->bss_generation++;
 106 }
 107
 108 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 109 {
 110         while (len > 2 && ies[0] != num) {
 111                 len -= ies[1] + 2;
 112                 ies += ies[1] + 2;
 113         }
 114         if (len < 2)
 115                 return NULL;
 116         if (len < 2 + ies[1])
 117                 return NULL;
 118         return ies;
 119 }
 120
 121 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 122 {
 123         const u8 *ie1 = find_ie(num, ies1, len1);
 124         const u8 *ie2 = find_ie(num, ies2, len2);
 125         int r;
 126
 127         if (!ie1 && !ie2)
 128                 return 0;
 129         if (!ie1)
 130                 return -1;
 131
 132         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 133         if (r == 0 && ie1[1] != ie2[1])
 134                 return ie2[1] - ie1[1];
 135         return r;
 136 }
 137
 138 static bool is_bss(struct cfg80211_bss *a,
 139                    const u8 *bssid,
 140                    const u8 *ssid, size_t ssid_len)
 141 {
 142         const u8 *ssidie;
 143
 144         if (bssid && compare_ether_addr(a->bssid, bssid))
 145                 return false;
 146
 147         if (!ssid)
 148                 return true;
 149
 150         ssidie = find_ie(WLAN_EID_SSID,
 151                          a->information_elements,
 152                          a->len_information_elements);
 153         if (!ssidie)
 154                 return false;
 155         if (ssidie[1] != ssid_len)
 156                 return false;
 157         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 158 }
 159
 160 static bool is_mesh(struct cfg80211_bss *a,
 161                     const u8 *meshid, size_t meshidlen,
 162                     const u8 *meshcfg)
 163 {
 164         const u8 *ie;
 165
 166         if (!is_zero_ether_addr(a->bssid))
 167                 return false;
 168
 169         ie = find_ie(WLAN_EID_MESH_ID,
 170                      a->information_elements,
 171                      a->len_information_elements);
 172         if (!ie)
 173                 return false;
 174         if (ie[1] != meshidlen)
 175                 return false;
 176         if (memcmp(ie + 2, meshid, meshidlen))
 177                 return false;
 178
 179         ie = find_ie(WLAN_EID_MESH_CONFIG,
 180                      a->information_elements,
 181                      a->len_information_elements);
 182         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 183                 return false;
 184
 185         /*
 186          * Ignore mesh capability (last two bytes of the IE) when
 187          * comparing since that may differ between stations taking
 188          * part in the same mesh.
 189          */
 190         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 191 }
 192
 193 static int cmp_bss(struct cfg80211_bss *a,
 194                    struct cfg80211_bss *b)
 195 {
 196         int r;
 197
 198         if (a->channel != b->channel)
 199                 return b->channel->center_freq - a->channel->center_freq;
 200
 201         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 202         if (r)
 203                 return r;
 204
 205         if (is_zero_ether_addr(a->bssid)) {
 206                 r = cmp_ies(WLAN_EID_MESH_ID,
 207                             a->information_elements,
 208                             a->len_information_elements,
 209                             b->information_elements,
 210                             b->len_information_elements);
 211                 if (r)
 212                         return r;
 213                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 214                                a->information_elements,
 215                                a->len_information_elements,
 216                                b->information_elements,
 217                                b->len_information_elements);
 218         }
 219
 220         return cmp_ies(WLAN_EID_SSID,
 221                        a->information_elements,
 222                        a->len_information_elements,
 223                        b->information_elements,
 224                        b->len_information_elements);
 225 }
 226
 227 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 228                                       struct ieee80211_channel *channel,
 229                                       const u8 *bssid,
 230                                       const u8 *ssid, size_t ssid_len,
 231                                       u16 capa_mask, u16 capa_val)
 232 {
 233         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 234         struct cfg80211_internal_bss *bss, *res = NULL;
 235
 236         spin_lock_bh(&dev->bss_lock);
 237
 238         list_for_each_entry(bss, &dev->bss_list, list) {
 239                 if ((bss->pub.capability & capa_mask) != capa_val)
 240                         continue;
 241                 if (channel && bss->pub.channel != channel)
 242                         continue;
 243                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 244                         res = bss;
 245                         kref_get(&res->ref);
 246                         break;
 247                 }
 248         }
 249
 250         spin_unlock_bh(&dev->bss_lock);
 251         if (!res)
 252                 return NULL;
 253         return &res->pub;
 254 }
 255 EXPORT_SYMBOL(cfg80211_get_bss);
 256
 257 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 258                                        struct ieee80211_channel *channel,
 259                                        const u8 *meshid, size_t meshidlen,
 260                                        const u8 *meshcfg)
 261 {
 262         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 263         struct cfg80211_internal_bss *bss, *res = NULL;
 264
 265         spin_lock_bh(&dev->bss_lock);
 266
 267         list_for_each_entry(bss, &dev->bss_list, list) {
 268                 if (channel && bss->pub.channel != channel)
 269                         continue;
 270                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 271                         res = bss;
 272                         kref_get(&res->ref);
 273                         break;
 274                 }
 275         }
 276
 277         spin_unlock_bh(&dev->bss_lock);
 278         if (!res)
 279                 return NULL;
 280         return &res->pub;
 281 }
 282 EXPORT_SYMBOL(cfg80211_get_mesh);
 283
 284
 285 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 286                           struct cfg80211_internal_bss *bss)
 287 {
 288         struct rb_node **p = &dev->bss_tree.rb_node;
 289         struct rb_node *parent = NULL;
 290         struct cfg80211_internal_bss *tbss;
 291         int cmp;
 292
 293         while (*p) {
 294                 parent = *p;
 295                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 296
 297                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 298
 299                 if (WARN_ON(!cmp)) {
 300                         /* will sort of leak this BSS */
 301                         return;
 302                 }
 303
 304                 if (cmp < 0)
 305                         p = &(*p)->rb_left;
 306                 else
 307                         p = &(*p)->rb_right;
 308         }
 309
 310         rb_link_node(&bss->rbn, parent, p);
 311         rb_insert_color(&bss->rbn, &dev->bss_tree);
 312 }
 313
 314 static struct cfg80211_internal_bss *
 315 rb_find_bss(struct cfg80211_registered_device *dev,
 316             struct cfg80211_internal_bss *res)
 317 {
 318         struct rb_node *n = dev->bss_tree.rb_node;
 319         struct cfg80211_internal_bss *bss;
 320         int r;
 321
 322         while (n) {
 323                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 324                 r = cmp_bss(&res->pub, &bss->pub);
 325
 326                 if (r == 0)
 327                         return bss;
 328                 else if (r < 0)
 329                         n = n->rb_left;
 330                 else
 331                         n = n->rb_right;
 332         }
 333
 334         return NULL;
 335 }
 336
 337 static struct cfg80211_internal_bss *
 338 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 339                     struct cfg80211_internal_bss *res,
 340                     bool overwrite)
 341 {
 342         struct cfg80211_internal_bss *found = NULL;
 343         const u8 *meshid, *meshcfg;
 344
 345         /*
 346          * The reference to "res" is donated to this function.
 347          */
 348
 349         if (WARN_ON(!res->pub.channel)) {
 350                 kref_put(&res->ref, bss_release);
 351                 return NULL;
 352         }
 353
 354         res->ts = jiffies;
 355
 356         if (is_zero_ether_addr(res->pub.bssid)) {
 357                 /* must be mesh, verify */
 358                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 359                                  res->pub.len_information_elements);
 360                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 361                                   res->pub.information_elements,
 362                                   res->pub.len_information_elements);
 363                 if (!meshid || !meshcfg ||
 364                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 365                         /* bogus mesh */
 366                         kref_put(&res->ref, bss_release);
 367                         return NULL;
 368                 }
 369         }
 370
 371         spin_lock_bh(&dev->bss_lock);
 372
 373         found = rb_find_bss(dev, res);
 374
 375         if (found) {
 376                 found->pub.beacon_interval = res->pub.beacon_interval;
 377                 found->pub.tsf = res->pub.tsf;
 378                 found->pub.signal = res->pub.signal;
 379                 found->pub.capability = res->pub.capability;
 380                 found->ts = res->ts;
 381
 382                 /* overwrite IEs */
 383                 if (overwrite) {
 384                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 385                         size_t ielen = res->pub.len_information_elements;
 386
 387                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 388                                 memcpy(found->pub.information_elements,
 389                                        res->pub.information_elements, ielen);
 390                                 found->pub.len_information_elements = ielen;
 391                         } else {
 392                                 u8 *ies = found->pub.information_elements;
 393
 394                                 if (found->ies_allocated)
 395                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 396                                 else
 397                                         ies = kmalloc(ielen, GFP_ATOMIC);
 398
 399                                 if (ies) {
 400                                         memcpy(ies, res->pub.information_elements, ielen);
 401                                         found->ies_allocated = true;
 402                                         found->pub.information_elements = ies;
 403                                         found->pub.len_information_elements = ielen;
 404                                 }
 405                         }
 406                 }
 407
 408                 kref_put(&res->ref, bss_release);
 409         } else {
 410                 /* this "consumes" the reference */
 411                 list_add_tail(&res->list, &dev->bss_list);
 412                 rb_insert_bss(dev, res);
 413                 found = res;
 414         }
 415
 416         dev->bss_generation++;
 417         spin_unlock_bh(&dev->bss_lock);
 418
 419         kref_get(&found->ref);
 420         return found;
 421 }
 422
 423 struct cfg80211_bss*
 424 cfg80211_inform_bss(struct wiphy *wiphy,
 425                     struct ieee80211_channel *channel,
 426                     const u8 *bssid,
 427                     u64 timestamp, u16 capability, u16 beacon_interval,
 428                     const u8 *ie, size_t ielen,
 429                     s32 signal, gfp_t gfp)
 430 {
 431         struct cfg80211_internal_bss *res;
 432         size_t privsz;
 433
 434         if (WARN_ON(!wiphy))
 435                 return NULL;
 436
 437         privsz = wiphy->bss_priv_size;
 438
 439         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 440                         (signal < 0 || signal > 100)))
 441                 return NULL;
 442
 443         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 444         if (!res)
 445                 return NULL;
 446
 447         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 448         res->pub.channel = channel;
 449         res->pub.signal = signal;
 450         res->pub.tsf = timestamp;
 451         res->pub.beacon_interval = beacon_interval;
 452         res->pub.capability = capability;
 453         /* point to after the private area */
 454         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 455         memcpy(res->pub.information_elements, ie, ielen);
 456         res->pub.len_information_elements = ielen;
 457
 458         kref_init(&res->ref);
 459
 460         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 461         if (!res)
 462                 return NULL;
 463
 464         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 465                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 466
 467         /* cfg80211_bss_update gives us a referenced result */
 468         return &res->pub;
 469 }
 470 EXPORT_SYMBOL(cfg80211_inform_bss);
 471
 472 struct cfg80211_bss *
 473 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 474                           struct ieee80211_channel *channel,
 475                           struct ieee80211_mgmt *mgmt, size_t len,
 476                           s32 signal, gfp_t gfp)
 477 {
 478         struct cfg80211_internal_bss *res;
 479         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 480                                       u.probe_resp.variable);
 481         bool overwrite;
 482         size_t privsz = wiphy->bss_priv_size;
 483
 484         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 485                     (signal < 0 || signal > 100)))
 486                 return NULL;
 487
 488         if (WARN_ON(!mgmt || !wiphy ||
 489                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 490                 return NULL;
 491
 492         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 493         if (!res)
 494                 return NULL;
 495
 496         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 497         res->pub.channel = channel;
 498         res->pub.signal = signal;
 499         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 500         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 501         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 502         /* point to after the private area */
 503         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 504         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 505         res->pub.len_information_elements = ielen;
 506
 507         kref_init(&res->ref);
 508
 509         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 510
 511         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 512         if (!res)
 513                 return NULL;
 514
 515         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 516                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 517
 518         /* cfg80211_bss_update gives us a referenced result */
 519         return &res->pub;
 520 }
 521 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 522
 523 void cfg80211_put_bss(struct cfg80211_bss *pub)
 524 {
 525         struct cfg80211_internal_bss *bss;
 526
 527         if (!pub)
 528                 return;
 529
 530         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 531         kref_put(&bss->ref, bss_release);
 532 }
 533 EXPORT_SYMBOL(cfg80211_put_bss);
 534
 535 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 536 {
 537         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 538         struct cfg80211_internal_bss *bss;
 539
 540         if (WARN_ON(!pub))
 541                 return;
 542
 543         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 544
 545         spin_lock_bh(&dev->bss_lock);
 546
 547         list_del(&bss->list);
 548         rb_erase(&bss->rbn, &dev->bss_tree);
 549
 550         spin_unlock_bh(&dev->bss_lock);
 551
 552         kref_put(&bss->ref, bss_release);
 553 }
 554 EXPORT_SYMBOL(cfg80211_unlink_bss);
 555
 556 void cfg80211_hold_bss(struct cfg80211_bss *pub)
 557 {
 558         struct cfg80211_internal_bss *bss;
 559
 560         if (!pub)
 561                 return;
 562
 563         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 564         bss->hold = true;
 565 }
 566 EXPORT_SYMBOL(cfg80211_hold_bss);
 567
 568 void cfg80211_unhold_bss(struct cfg80211_bss *pub)
 569 {
 570         struct cfg80211_internal_bss *bss;
 571
 572         if (!pub)
 573                 return;
 574
 575         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 576         bss->hold = false;
 577 }
 578 EXPORT_SYMBOL(cfg80211_unhold_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_put_dev(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_put_dev(rdev);
 970         return res;
 971 }
 972 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 973 #endif