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 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         if (aborted)
  34                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  35         else
  36                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  37
  38         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  39
  40 #ifdef CONFIG_WIRELESS_EXT
  41         if (!aborted) {
  42                 memset(&wrqu, 0, sizeof(wrqu));
  43
  44                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  45         }
  46 #endif
  47
  48         dev_put(dev);
  49
  50  out:
  51         kfree(request);
  52 }
  53 EXPORT_SYMBOL(cfg80211_scan_done);
  54
  55 static void bss_release(struct kref *ref)
  56 {
  57         struct cfg80211_internal_bss *bss;
  58
  59         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  60         if (bss->pub.free_priv)
  61                 bss->pub.free_priv(&bss->pub);
  62
  63         if (bss->ies_allocated)
  64                 kfree(bss->pub.information_elements);
  65
  66         kfree(bss);
  67 }
  68
  69 /* must hold dev->bss_lock! */
  70 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
  71                       unsigned long age_secs)
  72 {
  73         struct cfg80211_internal_bss *bss;
  74         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
  75
  76         list_for_each_entry(bss, &dev->bss_list, list) {
  77                 bss->ts -= age_jiffies;
  78         }
  79 }
  80
  81 /* must hold dev->bss_lock! */
  82 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
  83 {
  84         struct cfg80211_internal_bss *bss, *tmp;
  85         bool expired = false;
  86
  87         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
  88                 if (bss->hold ||
  89                     !time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
  90                         continue;
  91                 list_del(&bss->list);
  92                 rb_erase(&bss->rbn, &dev->bss_tree);
  93                 kref_put(&bss->ref, bss_release);
  94                 expired = true;
  95         }
  96
  97         if (expired)
  98                 dev->bss_generation++;
  99 }
 100
 101 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 102 {
 103         while (len > 2 && ies[0] != num) {
 104                 len -= ies[1] + 2;
 105                 ies += ies[1] + 2;
 106         }
 107         if (len < 2)
 108                 return NULL;
 109         if (len < 2 + ies[1])
 110                 return NULL;
 111         return ies;
 112 }
 113
 114 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 115 {
 116         const u8 *ie1 = find_ie(num, ies1, len1);
 117         const u8 *ie2 = find_ie(num, ies2, len2);
 118         int r;
 119
 120         if (!ie1 && !ie2)
 121                 return 0;
 122         if (!ie1)
 123                 return -1;
 124
 125         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 126         if (r == 0 && ie1[1] != ie2[1])
 127                 return ie2[1] - ie1[1];
 128         return r;
 129 }
 130
 131 static bool is_bss(struct cfg80211_bss *a,
 132                    const u8 *bssid,
 133                    const u8 *ssid, size_t ssid_len)
 134 {
 135         const u8 *ssidie;
 136
 137         if (bssid && compare_ether_addr(a->bssid, bssid))
 138                 return false;
 139
 140         if (!ssid)
 141                 return true;
 142
 143         ssidie = find_ie(WLAN_EID_SSID,
 144                          a->information_elements,
 145                          a->len_information_elements);
 146         if (!ssidie)
 147                 return false;
 148         if (ssidie[1] != ssid_len)
 149                 return false;
 150         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 151 }
 152
 153 static bool is_mesh(struct cfg80211_bss *a,
 154                     const u8 *meshid, size_t meshidlen,
 155                     const u8 *meshcfg)
 156 {
 157         const u8 *ie;
 158
 159         if (!is_zero_ether_addr(a->bssid))
 160                 return false;
 161
 162         ie = find_ie(WLAN_EID_MESH_ID,
 163                      a->information_elements,
 164                      a->len_information_elements);
 165         if (!ie)
 166                 return false;
 167         if (ie[1] != meshidlen)
 168                 return false;
 169         if (memcmp(ie + 2, meshid, meshidlen))
 170                 return false;
 171
 172         ie = find_ie(WLAN_EID_MESH_CONFIG,
 173                      a->information_elements,
 174                      a->len_information_elements);
 175         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 176                 return false;
 177
 178         /*
 179          * Ignore mesh capability (last two bytes of the IE) when
 180          * comparing since that may differ between stations taking
 181          * part in the same mesh.
 182          */
 183         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 184 }
 185
 186 static int cmp_bss(struct cfg80211_bss *a,
 187                    struct cfg80211_bss *b)
 188 {
 189         int r;
 190
 191         if (a->channel != b->channel)
 192                 return b->channel->center_freq - a->channel->center_freq;
 193
 194         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 195         if (r)
 196                 return r;
 197
 198         if (is_zero_ether_addr(a->bssid)) {
 199                 r = cmp_ies(WLAN_EID_MESH_ID,
 200                             a->information_elements,
 201                             a->len_information_elements,
 202                             b->information_elements,
 203                             b->len_information_elements);
 204                 if (r)
 205                         return r;
 206                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 207                                a->information_elements,
 208                                a->len_information_elements,
 209                                b->information_elements,
 210                                b->len_information_elements);
 211         }
 212
 213         return cmp_ies(WLAN_EID_SSID,
 214                        a->information_elements,
 215                        a->len_information_elements,
 216                        b->information_elements,
 217                        b->len_information_elements);
 218 }
 219
 220 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 221                                       struct ieee80211_channel *channel,
 222                                       const u8 *bssid,
 223                                       const u8 *ssid, size_t ssid_len,
 224                                       u16 capa_mask, u16 capa_val)
 225 {
 226         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 227         struct cfg80211_internal_bss *bss, *res = NULL;
 228
 229         spin_lock_bh(&dev->bss_lock);
 230
 231         list_for_each_entry(bss, &dev->bss_list, list) {
 232                 if ((bss->pub.capability & capa_mask) != capa_val)
 233                         continue;
 234                 if (channel && bss->pub.channel != channel)
 235                         continue;
 236                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 237                         res = bss;
 238                         kref_get(&res->ref);
 239                         break;
 240                 }
 241         }
 242
 243         spin_unlock_bh(&dev->bss_lock);
 244         if (!res)
 245                 return NULL;
 246         return &res->pub;
 247 }
 248 EXPORT_SYMBOL(cfg80211_get_bss);
 249
 250 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 251                                        struct ieee80211_channel *channel,
 252                                        const u8 *meshid, size_t meshidlen,
 253                                        const u8 *meshcfg)
 254 {
 255         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 256         struct cfg80211_internal_bss *bss, *res = NULL;
 257
 258         spin_lock_bh(&dev->bss_lock);
 259
 260         list_for_each_entry(bss, &dev->bss_list, list) {
 261                 if (channel && bss->pub.channel != channel)
 262                         continue;
 263                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 264                         res = bss;
 265                         kref_get(&res->ref);
 266                         break;
 267                 }
 268         }
 269
 270         spin_unlock_bh(&dev->bss_lock);
 271         if (!res)
 272                 return NULL;
 273         return &res->pub;
 274 }
 275 EXPORT_SYMBOL(cfg80211_get_mesh);
 276
 277
 278 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 279                           struct cfg80211_internal_bss *bss)
 280 {
 281         struct rb_node **p = &dev->bss_tree.rb_node;
 282         struct rb_node *parent = NULL;
 283         struct cfg80211_internal_bss *tbss;
 284         int cmp;
 285
 286         while (*p) {
 287                 parent = *p;
 288                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 289
 290                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 291
 292                 if (WARN_ON(!cmp)) {
 293                         /* will sort of leak this BSS */
 294                         return;
 295                 }
 296
 297                 if (cmp < 0)
 298                         p = &(*p)->rb_left;
 299                 else
 300                         p = &(*p)->rb_right;
 301         }
 302
 303         rb_link_node(&bss->rbn, parent, p);
 304         rb_insert_color(&bss->rbn, &dev->bss_tree);
 305 }
 306
 307 static struct cfg80211_internal_bss *
 308 rb_find_bss(struct cfg80211_registered_device *dev,
 309             struct cfg80211_internal_bss *res)
 310 {
 311         struct rb_node *n = dev->bss_tree.rb_node;
 312         struct cfg80211_internal_bss *bss;
 313         int r;
 314
 315         while (n) {
 316                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 317                 r = cmp_bss(&res->pub, &bss->pub);
 318
 319                 if (r == 0)
 320                         return bss;
 321                 else if (r < 0)
 322                         n = n->rb_left;
 323                 else
 324                         n = n->rb_right;
 325         }
 326
 327         return NULL;
 328 }
 329
 330 static struct cfg80211_internal_bss *
 331 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 332                     struct cfg80211_internal_bss *res,
 333                     bool overwrite)
 334 {
 335         struct cfg80211_internal_bss *found = NULL;
 336         const u8 *meshid, *meshcfg;
 337
 338         /*
 339          * The reference to "res" is donated to this function.
 340          */
 341
 342         if (WARN_ON(!res->pub.channel)) {
 343                 kref_put(&res->ref, bss_release);
 344                 return NULL;
 345         }
 346
 347         res->ts = jiffies;
 348
 349         if (is_zero_ether_addr(res->pub.bssid)) {
 350                 /* must be mesh, verify */
 351                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 352                                  res->pub.len_information_elements);
 353                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 354                                   res->pub.information_elements,
 355                                   res->pub.len_information_elements);
 356                 if (!meshid || !meshcfg ||
 357                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 358                         /* bogus mesh */
 359                         kref_put(&res->ref, bss_release);
 360                         return NULL;
 361                 }
 362         }
 363
 364         spin_lock_bh(&dev->bss_lock);
 365
 366         found = rb_find_bss(dev, res);
 367
 368         if (found) {
 369                 found->pub.beacon_interval = res->pub.beacon_interval;
 370                 found->pub.tsf = res->pub.tsf;
 371                 found->pub.signal = res->pub.signal;
 372                 found->pub.capability = res->pub.capability;
 373                 found->ts = res->ts;
 374
 375                 /* overwrite IEs */
 376                 if (overwrite) {
 377                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 378                         size_t ielen = res->pub.len_information_elements;
 379
 380                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 381                                 memcpy(found->pub.information_elements,
 382                                        res->pub.information_elements, ielen);
 383                                 found->pub.len_information_elements = ielen;
 384                         } else {
 385                                 u8 *ies = found->pub.information_elements;
 386
 387                                 if (found->ies_allocated)
 388                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 389                                 else
 390                                         ies = kmalloc(ielen, GFP_ATOMIC);
 391
 392                                 if (ies) {
 393                                         memcpy(ies, res->pub.information_elements, ielen);
 394                                         found->ies_allocated = true;
 395                                         found->pub.information_elements = ies;
 396                                         found->pub.len_information_elements = ielen;
 397                                 }
 398                         }
 399                 }
 400
 401                 kref_put(&res->ref, bss_release);
 402         } else {
 403                 /* this "consumes" the reference */
 404                 list_add_tail(&res->list, &dev->bss_list);
 405                 rb_insert_bss(dev, res);
 406                 found = res;
 407         }
 408
 409         dev->bss_generation++;
 410         spin_unlock_bh(&dev->bss_lock);
 411
 412         kref_get(&found->ref);
 413         return found;
 414 }
 415
 416 struct cfg80211_bss*
 417 cfg80211_inform_bss(struct wiphy *wiphy,
 418                     struct ieee80211_channel *channel,
 419                     const u8 *bssid,
 420                     u64 timestamp, u16 capability, u16 beacon_interval,
 421                     const u8 *ie, size_t ielen,
 422                     s32 signal, gfp_t gfp)
 423 {
 424         struct cfg80211_internal_bss *res;
 425         size_t privsz;
 426
 427         if (WARN_ON(!wiphy))
 428                 return NULL;
 429
 430         privsz = wiphy->bss_priv_size;
 431
 432         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 433                         (signal < 0 || signal > 100)))
 434                 return NULL;
 435
 436         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 437         if (!res)
 438                 return NULL;
 439
 440         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 441         res->pub.channel = channel;
 442         res->pub.signal = signal;
 443         res->pub.tsf = timestamp;
 444         res->pub.beacon_interval = beacon_interval;
 445         res->pub.capability = capability;
 446         /* point to after the private area */
 447         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 448         memcpy(res->pub.information_elements, ie, ielen);
 449         res->pub.len_information_elements = ielen;
 450
 451         kref_init(&res->ref);
 452
 453         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 454         if (!res)
 455                 return NULL;
 456
 457         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 458                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 459
 460         /* cfg80211_bss_update gives us a referenced result */
 461         return &res->pub;
 462 }
 463 EXPORT_SYMBOL(cfg80211_inform_bss);
 464
 465 struct cfg80211_bss *
 466 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 467                           struct ieee80211_channel *channel,
 468                           struct ieee80211_mgmt *mgmt, size_t len,
 469                           s32 signal, gfp_t gfp)
 470 {
 471         struct cfg80211_internal_bss *res;
 472         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 473                                       u.probe_resp.variable);
 474         bool overwrite;
 475         size_t 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         if (WARN_ON(!mgmt || !wiphy ||
 482                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 483                 return NULL;
 484
 485         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 486         if (!res)
 487                 return NULL;
 488
 489         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 490         res->pub.channel = channel;
 491         res->pub.signal = signal;
 492         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 493         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 494         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 495         /* point to after the private area */
 496         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 497         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 498         res->pub.len_information_elements = ielen;
 499
 500         kref_init(&res->ref);
 501
 502         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 503
 504         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 505         if (!res)
 506                 return NULL;
 507
 508         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 509                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 510
 511         /* cfg80211_bss_update gives us a referenced result */
 512         return &res->pub;
 513 }
 514 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 515
 516 void cfg80211_put_bss(struct cfg80211_bss *pub)
 517 {
 518         struct cfg80211_internal_bss *bss;
 519
 520         if (!pub)
 521                 return;
 522
 523         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 524         kref_put(&bss->ref, bss_release);
 525 }
 526 EXPORT_SYMBOL(cfg80211_put_bss);
 527
 528 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 529 {
 530         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 531         struct cfg80211_internal_bss *bss;
 532
 533         if (WARN_ON(!pub))
 534                 return;
 535
 536         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 537
 538         spin_lock_bh(&dev->bss_lock);
 539
 540         list_del(&bss->list);
 541         rb_erase(&bss->rbn, &dev->bss_tree);
 542
 543         spin_unlock_bh(&dev->bss_lock);
 544
 545         kref_put(&bss->ref, bss_release);
 546 }
 547 EXPORT_SYMBOL(cfg80211_unlink_bss);
 548
 549 void cfg80211_hold_bss(struct cfg80211_bss *pub)
 550 {
 551         struct cfg80211_internal_bss *bss;
 552
 553         if (!pub)
 554                 return;
 555
 556         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 557         bss->hold = true;
 558 }
 559 EXPORT_SYMBOL(cfg80211_hold_bss);
 560
 561 void cfg80211_unhold_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         bss->hold = false;
 570 }
 571 EXPORT_SYMBOL(cfg80211_unhold_bss);
 572
 573 #ifdef CONFIG_WIRELESS_EXT
 574 int cfg80211_wext_siwscan(struct net_device *dev,
 575                           struct iw_request_info *info,
 576                           union iwreq_data *wrqu, char *extra)
 577 {
 578         struct cfg80211_registered_device *rdev;
 579         struct wiphy *wiphy;
 580         struct iw_scan_req *wreq = NULL;
 581         struct cfg80211_scan_request *creq;
 582         int i, err, n_channels = 0;
 583         enum ieee80211_band band;
 584
 585         if (!netif_running(dev))
 586                 return -ENETDOWN;
 587
 588         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 589
 590         if (IS_ERR(rdev))
 591                 return PTR_ERR(rdev);
 592
 593         if (rdev->scan_req) {
 594                 err = -EBUSY;
 595                 goto out;
 596         }
 597
 598         wiphy = &rdev->wiphy;
 599
 600         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 601                 if (wiphy->bands[band])
 602                         n_channels += wiphy->bands[band]->n_channels;
 603
 604         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 605                        n_channels * sizeof(void *),
 606                        GFP_ATOMIC);
 607         if (!creq) {
 608                 err = -ENOMEM;
 609                 goto out;
 610         }
 611
 612         creq->wiphy = wiphy;
 613         creq->ifidx = dev->ifindex;
 614         creq->ssids = (void *)(creq + 1);
 615         creq->channels = (void *)(creq->ssids + 1);
 616         creq->n_channels = n_channels;
 617         creq->n_ssids = 1;
 618
 619         /* all channels */
 620         i = 0;
 621         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 622                 int j;
 623                 if (!wiphy->bands[band])
 624                         continue;
 625                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 626                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 627                         i++;
 628                 }
 629         }
 630
 631         /* translate scan request */
 632         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 633                 wreq = (struct iw_scan_req *)extra;
 634
 635                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 636                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 637                                 return -EINVAL;
 638                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 639                         creq->ssids[0].ssid_len = wreq->essid_len;
 640                 }
 641                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 642                         creq->n_ssids = 0;
 643         }
 644
 645         rdev->scan_req = creq;
 646         err = rdev->ops->scan(wiphy, dev, creq);
 647         if (err) {
 648                 rdev->scan_req = NULL;
 649                 kfree(creq);
 650         }
 651  out:
 652         cfg80211_put_dev(rdev);
 653         return err;
 654 }
 655 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 656
 657 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 658                                    struct cfg80211_bss *bss,
 659                                    char **current_ev, char *end_buf)
 660 {
 661         u8 *pos, *end, *next;
 662         struct iw_event iwe;
 663
 664         if (!bss->information_elements ||
 665             !bss->len_information_elements)
 666                 return;
 667
 668         /*
 669          * If needed, fragment the IEs buffer (at IE boundaries) into short
 670          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 671          */
 672         pos = bss->information_elements;
 673         end = pos + bss->len_information_elements;
 674
 675         while (end - pos > IW_GENERIC_IE_MAX) {
 676                 next = pos + 2 + pos[1];
 677                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 678                         next = next + 2 + next[1];
 679
 680                 memset(&iwe, 0, sizeof(iwe));
 681                 iwe.cmd = IWEVGENIE;
 682                 iwe.u.data.length = next - pos;
 683                 *current_ev = iwe_stream_add_point(info, *current_ev,
 684                                                    end_buf, &iwe, pos);
 685
 686                 pos = next;
 687         }
 688
 689         if (end > pos) {
 690                 memset(&iwe, 0, sizeof(iwe));
 691                 iwe.cmd = IWEVGENIE;
 692                 iwe.u.data.length = end - pos;
 693                 *current_ev = iwe_stream_add_point(info, *current_ev,
 694                                                    end_buf, &iwe, pos);
 695         }
 696 }
 697
 698 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 699 {
 700         unsigned long end = jiffies;
 701
 702         if (end >= start)
 703                 return jiffies_to_msecs(end - start);
 704
 705         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 706 }
 707
 708 static char *
 709 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 710               struct cfg80211_internal_bss *bss, char *current_ev,
 711               char *end_buf)
 712 {
 713         struct iw_event iwe;
 714         u8 *buf, *cfg, *p;
 715         u8 *ie = bss->pub.information_elements;
 716         int rem = bss->pub.len_information_elements, i, sig;
 717         bool ismesh = false;
 718
 719         memset(&iwe, 0, sizeof(iwe));
 720         iwe.cmd = SIOCGIWAP;
 721         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 722         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 723         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 724                                           IW_EV_ADDR_LEN);
 725
 726         memset(&iwe, 0, sizeof(iwe));
 727         iwe.cmd = SIOCGIWFREQ;
 728         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 729         iwe.u.freq.e = 0;
 730         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 731                                           IW_EV_FREQ_LEN);
 732
 733         memset(&iwe, 0, sizeof(iwe));
 734         iwe.cmd = SIOCGIWFREQ;
 735         iwe.u.freq.m = bss->pub.channel->center_freq;
 736         iwe.u.freq.e = 6;
 737         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 738                                           IW_EV_FREQ_LEN);
 739
 740         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 741                 memset(&iwe, 0, sizeof(iwe));
 742                 iwe.cmd = IWEVQUAL;
 743                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 744                                      IW_QUAL_NOISE_INVALID |
 745                                      IW_QUAL_QUAL_UPDATED;
 746                 switch (wiphy->signal_type) {
 747                 case CFG80211_SIGNAL_TYPE_MBM:
 748                         sig = bss->pub.signal / 100;
 749                         iwe.u.qual.level = sig;
 750                         iwe.u.qual.updated |= IW_QUAL_DBM;
 751                         if (sig < -110)         /* rather bad */
 752                                 sig = -110;
 753                         else if (sig > -40)     /* perfect */
 754                                 sig = -40;
 755                         /* will give a range of 0 .. 70 */
 756                         iwe.u.qual.qual = sig + 110;
 757                         break;
 758                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 759                         iwe.u.qual.level = bss->pub.signal;
 760                         /* will give range 0 .. 100 */
 761                         iwe.u.qual.qual = bss->pub.signal;
 762                         break;
 763                 default:
 764                         /* not reached */
 765                         break;
 766                 }
 767                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 768                                                   &iwe, IW_EV_QUAL_LEN);
 769         }
 770
 771         memset(&iwe, 0, sizeof(iwe));
 772         iwe.cmd = SIOCGIWENCODE;
 773         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 774                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 775         else
 776                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 777         iwe.u.data.length = 0;
 778         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 779                                           &iwe, "");
 780
 781         while (rem >= 2) {
 782                 /* invalid data */
 783                 if (ie[1] > rem - 2)
 784                         break;
 785
 786                 switch (ie[0]) {
 787                 case WLAN_EID_SSID:
 788                         memset(&iwe, 0, sizeof(iwe));
 789                         iwe.cmd = SIOCGIWESSID;
 790                         iwe.u.data.length = ie[1];
 791                         iwe.u.data.flags = 1;
 792                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 793                                                           &iwe, ie + 2);
 794                         break;
 795                 case WLAN_EID_MESH_ID:
 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_CONFIG:
 804                         ismesh = true;
 805                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 806                                 break;
 807                         buf = kmalloc(50, GFP_ATOMIC);
 808                         if (!buf)
 809                                 break;
 810                         cfg = ie + 2;
 811                         memset(&iwe, 0, sizeof(iwe));
 812                         iwe.cmd = IWEVCUSTOM;
 813                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 814                         iwe.u.data.length = strlen(buf);
 815                         current_ev = iwe_stream_add_point(info, current_ev,
 816                                                           end_buf,
 817                                                           &iwe, buf);
 818                         sprintf(buf, "Path Selection Protocol ID: "
 819                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 820                                                         cfg[4]);
 821                         iwe.u.data.length = strlen(buf);
 822                         current_ev = iwe_stream_add_point(info, current_ev,
 823                                                           end_buf,
 824                                                           &iwe, buf);
 825                         sprintf(buf, "Path Selection Metric ID: "
 826                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 827                                                         cfg[8]);
 828                         iwe.u.data.length = strlen(buf);
 829                         current_ev = iwe_stream_add_point(info, current_ev,
 830                                                           end_buf,
 831                                                           &iwe, buf);
 832                         sprintf(buf, "Congestion Control Mode ID: "
 833                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 834                                                         cfg[11], cfg[12]);
 835                         iwe.u.data.length = strlen(buf);
 836                         current_ev = iwe_stream_add_point(info, current_ev,
 837                                                           end_buf,
 838                                                           &iwe, buf);
 839                         sprintf(buf, "Channel Precedence: "
 840                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 841                                                         cfg[15], cfg[16]);
 842                         iwe.u.data.length = strlen(buf);
 843                         current_ev = iwe_stream_add_point(info, current_ev,
 844                                                           end_buf,
 845                                                           &iwe, buf);
 846                         kfree(buf);
 847                         break;
 848                 case WLAN_EID_SUPP_RATES:
 849                 case WLAN_EID_EXT_SUPP_RATES:
 850                         /* display all supported rates in readable format */
 851                         p = current_ev + iwe_stream_lcp_len(info);
 852
 853                         memset(&iwe, 0, sizeof(iwe));
 854                         iwe.cmd = SIOCGIWRATE;
 855                         /* Those two flags are ignored... */
 856                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 857
 858                         for (i = 0; i < ie[1]; i++) {
 859                                 iwe.u.bitrate.value =
 860                                         ((ie[i + 2] & 0x7f) * 500000);
 861                                 p = iwe_stream_add_value(info, current_ev, p,
 862                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 863                         }
 864                         current_ev = p;
 865                         break;
 866                 }
 867                 rem -= ie[1] + 2;
 868                 ie += ie[1] + 2;
 869         }
 870
 871         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 872             || ismesh) {
 873                 memset(&iwe, 0, sizeof(iwe));
 874                 iwe.cmd = SIOCGIWMODE;
 875                 if (ismesh)
 876                         iwe.u.mode = IW_MODE_MESH;
 877                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 878                         iwe.u.mode = IW_MODE_MASTER;
 879                 else
 880                         iwe.u.mode = IW_MODE_ADHOC;
 881                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 882                                                   &iwe, IW_EV_UINT_LEN);
 883         }
 884
 885         buf = kmalloc(30, GFP_ATOMIC);
 886         if (buf) {
 887                 memset(&iwe, 0, sizeof(iwe));
 888                 iwe.cmd = IWEVCUSTOM;
 889                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 890                 iwe.u.data.length = strlen(buf);
 891                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 892                                                   &iwe, buf);
 893                 memset(&iwe, 0, sizeof(iwe));
 894                 iwe.cmd = IWEVCUSTOM;
 895                 sprintf(buf, " Last beacon: %ums ago",
 896                         elapsed_jiffies_msecs(bss->ts));
 897                 iwe.u.data.length = strlen(buf);
 898                 current_ev = iwe_stream_add_point(info, current_ev,
 899                                                   end_buf, &iwe, buf);
 900                 kfree(buf);
 901         }
 902
 903         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 904
 905         return current_ev;
 906 }
 907
 908
 909 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 910                                   struct iw_request_info *info,
 911                                   char *buf, size_t len)
 912 {
 913         char *current_ev = buf;
 914         char *end_buf = buf + len;
 915         struct cfg80211_internal_bss *bss;
 916
 917         spin_lock_bh(&dev->bss_lock);
 918         cfg80211_bss_expire(dev);
 919
 920         list_for_each_entry(bss, &dev->bss_list, list) {
 921                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 922                         spin_unlock_bh(&dev->bss_lock);
 923                         return -E2BIG;
 924                 }
 925                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 926                                            current_ev, end_buf);
 927         }
 928         spin_unlock_bh(&dev->bss_lock);
 929         return current_ev - buf;
 930 }
 931
 932
 933 int cfg80211_wext_giwscan(struct net_device *dev,
 934                           struct iw_request_info *info,
 935                           struct iw_point *data, char *extra)
 936 {
 937         struct cfg80211_registered_device *rdev;
 938         int res;
 939
 940         if (!netif_running(dev))
 941                 return -ENETDOWN;
 942
 943         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 944
 945         if (IS_ERR(rdev))
 946                 return PTR_ERR(rdev);
 947
 948         if (rdev->scan_req) {
 949                 res = -EAGAIN;
 950                 goto out;
 951         }
 952
 953         res = ieee80211_scan_results(rdev, info, extra, data->length);
 954         data->length = 0;
 955         if (res >= 0) {
 956                 data->length = res;
 957                 res = 0;
 958         }
 959
 960  out:
 961         cfg80211_put_dev(rdev);
 962         return res;
 963 }
 964 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 965 #endif