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 #ifdef CONFIG_WIRELESS_EXT
  39         if (!aborted) {
  40                 memset(&wrqu, 0, sizeof(wrqu));
  41
  42                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  43         }
  44 #endif
  45
  46         dev_put(dev);
  47
  48  out:
  49         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  50         kfree(request);
  51 }
  52 EXPORT_SYMBOL(cfg80211_scan_done);
  53
  54 static void bss_release(struct kref *ref)
  55 {
  56         struct cfg80211_internal_bss *bss;
  57
  58         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  59         if (bss->pub.free_priv)
  60                 bss->pub.free_priv(&bss->pub);
  61
  62         if (bss->ies_allocated)
  63                 kfree(bss->pub.information_elements);
  64
  65         kfree(bss);
  66 }
  67
  68 /* must hold dev->bss_lock! */
  69 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
  70                       unsigned long age_secs)
  71 {
  72         struct cfg80211_internal_bss *bss;
  73         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
  74
  75         list_for_each_entry(bss, &dev->bss_list, list) {
  76                 bss->ts -= age_jiffies;
  77         }
  78 }
  79
  80 /* must hold dev->bss_lock! */
  81 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
  82 {
  83         struct cfg80211_internal_bss *bss, *tmp;
  84         bool expired = false;
  85
  86         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
  87                 if (bss->hold ||
  88                     !time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
  89                         continue;
  90                 list_del(&bss->list);
  91                 rb_erase(&bss->rbn, &dev->bss_tree);
  92                 kref_put(&bss->ref, bss_release);
  93                 expired = true;
  94         }
  95
  96         if (expired)
  97                 dev->bss_generation++;
  98 }
  99
 100 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 101 {
 102         while (len > 2 && ies[0] != num) {
 103                 len -= ies[1] + 2;
 104                 ies += ies[1] + 2;
 105         }
 106         if (len < 2)
 107                 return NULL;
 108         if (len < 2 + ies[1])
 109                 return NULL;
 110         return ies;
 111 }
 112
 113 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 114 {
 115         const u8 *ie1 = find_ie(num, ies1, len1);
 116         const u8 *ie2 = find_ie(num, ies2, len2);
 117         int r;
 118
 119         if (!ie1 && !ie2)
 120                 return 0;
 121         if (!ie1)
 122                 return -1;
 123
 124         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 125         if (r == 0 && ie1[1] != ie2[1])
 126                 return ie2[1] - ie1[1];
 127         return r;
 128 }
 129
 130 static bool is_bss(struct cfg80211_bss *a,
 131                    const u8 *bssid,
 132                    const u8 *ssid, size_t ssid_len)
 133 {
 134         const u8 *ssidie;
 135
 136         if (bssid && compare_ether_addr(a->bssid, bssid))
 137                 return false;
 138
 139         if (!ssid)
 140                 return true;
 141
 142         ssidie = find_ie(WLAN_EID_SSID,
 143                          a->information_elements,
 144                          a->len_information_elements);
 145         if (!ssidie)
 146                 return false;
 147         if (ssidie[1] != ssid_len)
 148                 return false;
 149         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 150 }
 151
 152 static bool is_mesh(struct cfg80211_bss *a,
 153                     const u8 *meshid, size_t meshidlen,
 154                     const u8 *meshcfg)
 155 {
 156         const u8 *ie;
 157
 158         if (!is_zero_ether_addr(a->bssid))
 159                 return false;
 160
 161         ie = find_ie(WLAN_EID_MESH_ID,
 162                      a->information_elements,
 163                      a->len_information_elements);
 164         if (!ie)
 165                 return false;
 166         if (ie[1] != meshidlen)
 167                 return false;
 168         if (memcmp(ie + 2, meshid, meshidlen))
 169                 return false;
 170
 171         ie = find_ie(WLAN_EID_MESH_CONFIG,
 172                      a->information_elements,
 173                      a->len_information_elements);
 174         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 175                 return false;
 176
 177         /*
 178          * Ignore mesh capability (last two bytes of the IE) when
 179          * comparing since that may differ between stations taking
 180          * part in the same mesh.
 181          */
 182         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 183 }
 184
 185 static int cmp_bss(struct cfg80211_bss *a,
 186                    struct cfg80211_bss *b)
 187 {
 188         int r;
 189
 190         if (a->channel != b->channel)
 191                 return b->channel->center_freq - a->channel->center_freq;
 192
 193         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 194         if (r)
 195                 return r;
 196
 197         if (is_zero_ether_addr(a->bssid)) {
 198                 r = cmp_ies(WLAN_EID_MESH_ID,
 199                             a->information_elements,
 200                             a->len_information_elements,
 201                             b->information_elements,
 202                             b->len_information_elements);
 203                 if (r)
 204                         return r;
 205                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 206                                a->information_elements,
 207                                a->len_information_elements,
 208                                b->information_elements,
 209                                b->len_information_elements);
 210         }
 211
 212         return cmp_ies(WLAN_EID_SSID,
 213                        a->information_elements,
 214                        a->len_information_elements,
 215                        b->information_elements,
 216                        b->len_information_elements);
 217 }
 218
 219 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 220                                       struct ieee80211_channel *channel,
 221                                       const u8 *bssid,
 222                                       const u8 *ssid, size_t ssid_len,
 223                                       u16 capa_mask, u16 capa_val)
 224 {
 225         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 226         struct cfg80211_internal_bss *bss, *res = NULL;
 227
 228         spin_lock_bh(&dev->bss_lock);
 229
 230         list_for_each_entry(bss, &dev->bss_list, list) {
 231                 if ((bss->pub.capability & capa_mask) != capa_val)
 232                         continue;
 233                 if (channel && bss->pub.channel != channel)
 234                         continue;
 235                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 236                         res = bss;
 237                         kref_get(&res->ref);
 238                         break;
 239                 }
 240         }
 241
 242         spin_unlock_bh(&dev->bss_lock);
 243         if (!res)
 244                 return NULL;
 245         return &res->pub;
 246 }
 247 EXPORT_SYMBOL(cfg80211_get_bss);
 248
 249 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 250                                        struct ieee80211_channel *channel,
 251                                        const u8 *meshid, size_t meshidlen,
 252                                        const u8 *meshcfg)
 253 {
 254         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 255         struct cfg80211_internal_bss *bss, *res = NULL;
 256
 257         spin_lock_bh(&dev->bss_lock);
 258
 259         list_for_each_entry(bss, &dev->bss_list, list) {
 260                 if (channel && bss->pub.channel != channel)
 261                         continue;
 262                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 263                         res = bss;
 264                         kref_get(&res->ref);
 265                         break;
 266                 }
 267         }
 268
 269         spin_unlock_bh(&dev->bss_lock);
 270         if (!res)
 271                 return NULL;
 272         return &res->pub;
 273 }
 274 EXPORT_SYMBOL(cfg80211_get_mesh);
 275
 276
 277 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 278                           struct cfg80211_internal_bss *bss)
 279 {
 280         struct rb_node **p = &dev->bss_tree.rb_node;
 281         struct rb_node *parent = NULL;
 282         struct cfg80211_internal_bss *tbss;
 283         int cmp;
 284
 285         while (*p) {
 286                 parent = *p;
 287                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 288
 289                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 290
 291                 if (WARN_ON(!cmp)) {
 292                         /* will sort of leak this BSS */
 293                         return;
 294                 }
 295
 296                 if (cmp < 0)
 297                         p = &(*p)->rb_left;
 298                 else
 299                         p = &(*p)->rb_right;
 300         }
 301
 302         rb_link_node(&bss->rbn, parent, p);
 303         rb_insert_color(&bss->rbn, &dev->bss_tree);
 304 }
 305
 306 static struct cfg80211_internal_bss *
 307 rb_find_bss(struct cfg80211_registered_device *dev,
 308             struct cfg80211_internal_bss *res)
 309 {
 310         struct rb_node *n = dev->bss_tree.rb_node;
 311         struct cfg80211_internal_bss *bss;
 312         int r;
 313
 314         while (n) {
 315                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 316                 r = cmp_bss(&res->pub, &bss->pub);
 317
 318                 if (r == 0)
 319                         return bss;
 320                 else if (r < 0)
 321                         n = n->rb_left;
 322                 else
 323                         n = n->rb_right;
 324         }
 325
 326         return NULL;
 327 }
 328
 329 static struct cfg80211_internal_bss *
 330 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 331                     struct cfg80211_internal_bss *res,
 332                     bool overwrite)
 333 {
 334         struct cfg80211_internal_bss *found = NULL;
 335         const u8 *meshid, *meshcfg;
 336
 337         /*
 338          * The reference to "res" is donated to this function.
 339          */
 340
 341         if (WARN_ON(!res->pub.channel)) {
 342                 kref_put(&res->ref, bss_release);
 343                 return NULL;
 344         }
 345
 346         res->ts = jiffies;
 347
 348         if (is_zero_ether_addr(res->pub.bssid)) {
 349                 /* must be mesh, verify */
 350                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 351                                  res->pub.len_information_elements);
 352                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 353                                   res->pub.information_elements,
 354                                   res->pub.len_information_elements);
 355                 if (!meshid || !meshcfg ||
 356                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 357                         /* bogus mesh */
 358                         kref_put(&res->ref, bss_release);
 359                         return NULL;
 360                 }
 361         }
 362
 363         spin_lock_bh(&dev->bss_lock);
 364
 365         found = rb_find_bss(dev, res);
 366
 367         if (found) {
 368                 found->pub.beacon_interval = res->pub.beacon_interval;
 369                 found->pub.tsf = res->pub.tsf;
 370                 found->pub.signal = res->pub.signal;
 371                 found->pub.capability = res->pub.capability;
 372                 found->ts = res->ts;
 373
 374                 /* overwrite IEs */
 375                 if (overwrite) {
 376                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 377                         size_t ielen = res->pub.len_information_elements;
 378
 379                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 380                                 memcpy(found->pub.information_elements,
 381                                        res->pub.information_elements, ielen);
 382                                 found->pub.len_information_elements = ielen;
 383                         } else {
 384                                 u8 *ies = found->pub.information_elements;
 385
 386                                 if (found->ies_allocated)
 387                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 388                                 else
 389                                         ies = kmalloc(ielen, GFP_ATOMIC);
 390
 391                                 if (ies) {
 392                                         memcpy(ies, res->pub.information_elements, ielen);
 393                                         found->ies_allocated = true;
 394                                         found->pub.information_elements = ies;
 395                                         found->pub.len_information_elements = ielen;
 396                                 }
 397                         }
 398                 }
 399
 400                 kref_put(&res->ref, bss_release);
 401         } else {
 402                 /* this "consumes" the reference */
 403                 list_add_tail(&res->list, &dev->bss_list);
 404                 rb_insert_bss(dev, res);
 405                 found = res;
 406         }
 407
 408         dev->bss_generation++;
 409         spin_unlock_bh(&dev->bss_lock);
 410
 411         kref_get(&found->ref);
 412         return found;
 413 }
 414
 415 struct cfg80211_bss*
 416 cfg80211_inform_bss(struct wiphy *wiphy,
 417                     struct ieee80211_channel *channel,
 418                     const u8 *bssid,
 419                     u64 timestamp, u16 capability, u16 beacon_interval,
 420                     const u8 *ie, size_t ielen,
 421                     s32 signal, gfp_t gfp)
 422 {
 423         struct cfg80211_internal_bss *res;
 424         size_t privsz;
 425
 426         if (WARN_ON(!wiphy))
 427                 return NULL;
 428
 429         privsz = wiphy->bss_priv_size;
 430
 431         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 432                         (signal < 0 || signal > 100)))
 433                 return NULL;
 434
 435         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 436         if (!res)
 437                 return NULL;
 438
 439         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 440         res->pub.channel = channel;
 441         res->pub.signal = signal;
 442         res->pub.tsf = timestamp;
 443         res->pub.beacon_interval = beacon_interval;
 444         res->pub.capability = capability;
 445         /* point to after the private area */
 446         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 447         memcpy(res->pub.information_elements, ie, ielen);
 448         res->pub.len_information_elements = ielen;
 449
 450         kref_init(&res->ref);
 451
 452         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 453         if (!res)
 454                 return NULL;
 455
 456         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 457                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 458
 459         /* cfg80211_bss_update gives us a referenced result */
 460         return &res->pub;
 461 }
 462 EXPORT_SYMBOL(cfg80211_inform_bss);
 463
 464 struct cfg80211_bss *
 465 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 466                           struct ieee80211_channel *channel,
 467                           struct ieee80211_mgmt *mgmt, size_t len,
 468                           s32 signal, gfp_t gfp)
 469 {
 470         struct cfg80211_internal_bss *res;
 471         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 472                                       u.probe_resp.variable);
 473         bool overwrite;
 474         size_t privsz = wiphy->bss_priv_size;
 475
 476         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 477                     (signal < 0 || signal > 100)))
 478                 return NULL;
 479
 480         if (WARN_ON(!mgmt || !wiphy ||
 481                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 482                 return NULL;
 483
 484         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 485         if (!res)
 486                 return NULL;
 487
 488         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 489         res->pub.channel = channel;
 490         res->pub.signal = signal;
 491         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 492         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 493         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 494         /* point to after the private area */
 495         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 496         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 497         res->pub.len_information_elements = ielen;
 498
 499         kref_init(&res->ref);
 500
 501         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 502
 503         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 504         if (!res)
 505                 return NULL;
 506
 507         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 508                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 509
 510         /* cfg80211_bss_update gives us a referenced result */
 511         return &res->pub;
 512 }
 513 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 514
 515 void cfg80211_put_bss(struct cfg80211_bss *pub)
 516 {
 517         struct cfg80211_internal_bss *bss;
 518
 519         if (!pub)
 520                 return;
 521
 522         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 523         kref_put(&bss->ref, bss_release);
 524 }
 525 EXPORT_SYMBOL(cfg80211_put_bss);
 526
 527 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 528 {
 529         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 530         struct cfg80211_internal_bss *bss;
 531
 532         if (WARN_ON(!pub))
 533                 return;
 534
 535         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 536
 537         spin_lock_bh(&dev->bss_lock);
 538
 539         list_del(&bss->list);
 540         rb_erase(&bss->rbn, &dev->bss_tree);
 541
 542         spin_unlock_bh(&dev->bss_lock);
 543
 544         kref_put(&bss->ref, bss_release);
 545 }
 546 EXPORT_SYMBOL(cfg80211_unlink_bss);
 547
 548 void cfg80211_hold_bss(struct cfg80211_bss *pub)
 549 {
 550         struct cfg80211_internal_bss *bss;
 551
 552         if (!pub)
 553                 return;
 554
 555         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 556         bss->hold = true;
 557 }
 558 EXPORT_SYMBOL(cfg80211_hold_bss);
 559
 560 void cfg80211_unhold_bss(struct cfg80211_bss *pub)
 561 {
 562         struct cfg80211_internal_bss *bss;
 563
 564         if (!pub)
 565                 return;
 566
 567         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 568         bss->hold = false;
 569 }
 570 EXPORT_SYMBOL(cfg80211_unhold_bss);
 571
 572 #ifdef CONFIG_WIRELESS_EXT
 573 int cfg80211_wext_siwscan(struct net_device *dev,
 574                           struct iw_request_info *info,
 575                           union iwreq_data *wrqu, char *extra)
 576 {
 577         struct cfg80211_registered_device *rdev;
 578         struct wiphy *wiphy;
 579         struct iw_scan_req *wreq = NULL;
 580         struct cfg80211_scan_request *creq;
 581         int i, err, n_channels = 0;
 582         enum ieee80211_band band;
 583
 584         if (!netif_running(dev))
 585                 return -ENETDOWN;
 586
 587         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 588
 589         if (IS_ERR(rdev))
 590                 return PTR_ERR(rdev);
 591
 592         if (rdev->scan_req) {
 593                 err = -EBUSY;
 594                 goto out;
 595         }
 596
 597         wiphy = &rdev->wiphy;
 598
 599         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 600                 if (wiphy->bands[band])
 601                         n_channels += wiphy->bands[band]->n_channels;
 602
 603         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 604                        n_channels * sizeof(void *),
 605                        GFP_ATOMIC);
 606         if (!creq) {
 607                 err = -ENOMEM;
 608                 goto out;
 609         }
 610
 611         creq->wiphy = wiphy;
 612         creq->ifidx = dev->ifindex;
 613         creq->ssids = (void *)(creq + 1);
 614         creq->channels = (void *)(creq->ssids + 1);
 615         creq->n_channels = n_channels;
 616         creq->n_ssids = 1;
 617
 618         /* all channels */
 619         i = 0;
 620         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 621                 int j;
 622                 if (!wiphy->bands[band])
 623                         continue;
 624                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 625                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 626                         i++;
 627                 }
 628         }
 629
 630         /* translate scan request */
 631         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 632                 wreq = (struct iw_scan_req *)extra;
 633
 634                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 635                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 636                                 return -EINVAL;
 637                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 638                         creq->ssids[0].ssid_len = wreq->essid_len;
 639                 }
 640                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 641                         creq->n_ssids = 0;
 642         }
 643
 644         rdev->scan_req = creq;
 645         err = rdev->ops->scan(wiphy, dev, creq);
 646         if (err) {
 647                 rdev->scan_req = NULL;
 648                 kfree(creq);
 649         }
 650  out:
 651         cfg80211_put_dev(rdev);
 652         return err;
 653 }
 654 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 655
 656 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 657                                    struct cfg80211_bss *bss,
 658                                    char **current_ev, char *end_buf)
 659 {
 660         u8 *pos, *end, *next;
 661         struct iw_event iwe;
 662
 663         if (!bss->information_elements ||
 664             !bss->len_information_elements)
 665                 return;
 666
 667         /*
 668          * If needed, fragment the IEs buffer (at IE boundaries) into short
 669          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 670          */
 671         pos = bss->information_elements;
 672         end = pos + bss->len_information_elements;
 673
 674         while (end - pos > IW_GENERIC_IE_MAX) {
 675                 next = pos + 2 + pos[1];
 676                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 677                         next = next + 2 + next[1];
 678
 679                 memset(&iwe, 0, sizeof(iwe));
 680                 iwe.cmd = IWEVGENIE;
 681                 iwe.u.data.length = next - pos;
 682                 *current_ev = iwe_stream_add_point(info, *current_ev,
 683                                                    end_buf, &iwe, pos);
 684
 685                 pos = next;
 686         }
 687
 688         if (end > pos) {
 689                 memset(&iwe, 0, sizeof(iwe));
 690                 iwe.cmd = IWEVGENIE;
 691                 iwe.u.data.length = end - pos;
 692                 *current_ev = iwe_stream_add_point(info, *current_ev,
 693                                                    end_buf, &iwe, pos);
 694         }
 695 }
 696
 697 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 698 {
 699         unsigned long end = jiffies;
 700
 701         if (end >= start)
 702                 return jiffies_to_msecs(end - start);
 703
 704         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 705 }
 706
 707 static char *
 708 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 709               struct cfg80211_internal_bss *bss, char *current_ev,
 710               char *end_buf)
 711 {
 712         struct iw_event iwe;
 713         u8 *buf, *cfg, *p;
 714         u8 *ie = bss->pub.information_elements;
 715         int rem = bss->pub.len_information_elements, i, sig;
 716         bool ismesh = false;
 717
 718         memset(&iwe, 0, sizeof(iwe));
 719         iwe.cmd = SIOCGIWAP;
 720         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 721         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 722         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 723                                           IW_EV_ADDR_LEN);
 724
 725         memset(&iwe, 0, sizeof(iwe));
 726         iwe.cmd = SIOCGIWFREQ;
 727         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 728         iwe.u.freq.e = 0;
 729         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 730                                           IW_EV_FREQ_LEN);
 731
 732         memset(&iwe, 0, sizeof(iwe));
 733         iwe.cmd = SIOCGIWFREQ;
 734         iwe.u.freq.m = bss->pub.channel->center_freq;
 735         iwe.u.freq.e = 6;
 736         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 737                                           IW_EV_FREQ_LEN);
 738
 739         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 740                 memset(&iwe, 0, sizeof(iwe));
 741                 iwe.cmd = IWEVQUAL;
 742                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 743                                      IW_QUAL_NOISE_INVALID |
 744                                      IW_QUAL_QUAL_UPDATED;
 745                 switch (wiphy->signal_type) {
 746                 case CFG80211_SIGNAL_TYPE_MBM:
 747                         sig = bss->pub.signal / 100;
 748                         iwe.u.qual.level = sig;
 749                         iwe.u.qual.updated |= IW_QUAL_DBM;
 750                         if (sig < -110)         /* rather bad */
 751                                 sig = -110;
 752                         else if (sig > -40)     /* perfect */
 753                                 sig = -40;
 754                         /* will give a range of 0 .. 70 */
 755                         iwe.u.qual.qual = sig + 110;
 756                         break;
 757                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 758                         iwe.u.qual.level = bss->pub.signal;
 759                         /* will give range 0 .. 100 */
 760                         iwe.u.qual.qual = bss->pub.signal;
 761                         break;
 762                 default:
 763                         /* not reached */
 764                         break;
 765                 }
 766                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 767                                                   &iwe, IW_EV_QUAL_LEN);
 768         }
 769
 770         memset(&iwe, 0, sizeof(iwe));
 771         iwe.cmd = SIOCGIWENCODE;
 772         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 773                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 774         else
 775                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 776         iwe.u.data.length = 0;
 777         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 778                                           &iwe, "");
 779
 780         while (rem >= 2) {
 781                 /* invalid data */
 782                 if (ie[1] > rem - 2)
 783                         break;
 784
 785                 switch (ie[0]) {
 786                 case WLAN_EID_SSID:
 787                         memset(&iwe, 0, sizeof(iwe));
 788                         iwe.cmd = SIOCGIWESSID;
 789                         iwe.u.data.length = ie[1];
 790                         iwe.u.data.flags = 1;
 791                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 792                                                           &iwe, ie + 2);
 793                         break;
 794                 case WLAN_EID_MESH_ID:
 795                         memset(&iwe, 0, sizeof(iwe));
 796                         iwe.cmd = SIOCGIWESSID;
 797                         iwe.u.data.length = ie[1];
 798                         iwe.u.data.flags = 1;
 799                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 800                                                           &iwe, ie + 2);
 801                         break;
 802                 case WLAN_EID_MESH_CONFIG:
 803                         ismesh = true;
 804                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 805                                 break;
 806                         buf = kmalloc(50, GFP_ATOMIC);
 807                         if (!buf)
 808                                 break;
 809                         cfg = ie + 2;
 810                         memset(&iwe, 0, sizeof(iwe));
 811                         iwe.cmd = IWEVCUSTOM;
 812                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 813                         iwe.u.data.length = strlen(buf);
 814                         current_ev = iwe_stream_add_point(info, current_ev,
 815                                                           end_buf,
 816                                                           &iwe, buf);
 817                         sprintf(buf, "Path Selection Protocol ID: "
 818                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 819                                                         cfg[4]);
 820                         iwe.u.data.length = strlen(buf);
 821                         current_ev = iwe_stream_add_point(info, current_ev,
 822                                                           end_buf,
 823                                                           &iwe, buf);
 824                         sprintf(buf, "Path Selection Metric ID: "
 825                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 826                                                         cfg[8]);
 827                         iwe.u.data.length = strlen(buf);
 828                         current_ev = iwe_stream_add_point(info, current_ev,
 829                                                           end_buf,
 830                                                           &iwe, buf);
 831                         sprintf(buf, "Congestion Control Mode ID: "
 832                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 833                                                         cfg[11], cfg[12]);
 834                         iwe.u.data.length = strlen(buf);
 835                         current_ev = iwe_stream_add_point(info, current_ev,
 836                                                           end_buf,
 837                                                           &iwe, buf);
 838                         sprintf(buf, "Channel Precedence: "
 839                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 840                                                         cfg[15], cfg[16]);
 841                         iwe.u.data.length = strlen(buf);
 842                         current_ev = iwe_stream_add_point(info, current_ev,
 843                                                           end_buf,
 844                                                           &iwe, buf);
 845                         kfree(buf);
 846                         break;
 847                 case WLAN_EID_SUPP_RATES:
 848                 case WLAN_EID_EXT_SUPP_RATES:
 849                         /* display all supported rates in readable format */
 850                         p = current_ev + iwe_stream_lcp_len(info);
 851
 852                         memset(&iwe, 0, sizeof(iwe));
 853                         iwe.cmd = SIOCGIWRATE;
 854                         /* Those two flags are ignored... */
 855                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 856
 857                         for (i = 0; i < ie[1]; i++) {
 858                                 iwe.u.bitrate.value =
 859                                         ((ie[i + 2] & 0x7f) * 500000);
 860                                 p = iwe_stream_add_value(info, current_ev, p,
 861                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 862                         }
 863                         current_ev = p;
 864                         break;
 865                 }
 866                 rem -= ie[1] + 2;
 867                 ie += ie[1] + 2;
 868         }
 869
 870         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 871             || ismesh) {
 872                 memset(&iwe, 0, sizeof(iwe));
 873                 iwe.cmd = SIOCGIWMODE;
 874                 if (ismesh)
 875                         iwe.u.mode = IW_MODE_MESH;
 876                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 877                         iwe.u.mode = IW_MODE_MASTER;
 878                 else
 879                         iwe.u.mode = IW_MODE_ADHOC;
 880                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 881                                                   &iwe, IW_EV_UINT_LEN);
 882         }
 883
 884         buf = kmalloc(30, GFP_ATOMIC);
 885         if (buf) {
 886                 memset(&iwe, 0, sizeof(iwe));
 887                 iwe.cmd = IWEVCUSTOM;
 888                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 889                 iwe.u.data.length = strlen(buf);
 890                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 891                                                   &iwe, buf);
 892                 memset(&iwe, 0, sizeof(iwe));
 893                 iwe.cmd = IWEVCUSTOM;
 894                 sprintf(buf, " Last beacon: %ums ago",
 895                         elapsed_jiffies_msecs(bss->ts));
 896                 iwe.u.data.length = strlen(buf);
 897                 current_ev = iwe_stream_add_point(info, current_ev,
 898                                                   end_buf, &iwe, buf);
 899                 kfree(buf);
 900         }
 901
 902         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 903
 904         return current_ev;
 905 }
 906
 907
 908 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 909                                   struct iw_request_info *info,
 910                                   char *buf, size_t len)
 911 {
 912         char *current_ev = buf;
 913         char *end_buf = buf + len;
 914         struct cfg80211_internal_bss *bss;
 915
 916         spin_lock_bh(&dev->bss_lock);
 917         cfg80211_bss_expire(dev);
 918
 919         list_for_each_entry(bss, &dev->bss_list, list) {
 920                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 921                         spin_unlock_bh(&dev->bss_lock);
 922                         return -E2BIG;
 923                 }
 924                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 925                                            current_ev, end_buf);
 926         }
 927         spin_unlock_bh(&dev->bss_lock);
 928         return current_ev - buf;
 929 }
 930
 931
 932 int cfg80211_wext_giwscan(struct net_device *dev,
 933                           struct iw_request_info *info,
 934                           struct iw_point *data, char *extra)
 935 {
 936         struct cfg80211_registered_device *rdev;
 937         int res;
 938
 939         if (!netif_running(dev))
 940                 return -ENETDOWN;
 941
 942         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 943
 944         if (IS_ERR(rdev))
 945                 return PTR_ERR(rdev);
 946
 947         if (rdev->scan_req) {
 948                 res = -EAGAIN;
 949                 goto out;
 950         }
 951
 952         res = ieee80211_scan_results(rdev, info, extra, data->length);
 953         data->length = 0;
 954         if (res >= 0) {
 955                 data->length = res;
 956                 res = 0;
 957         }
 958
 959  out:
 960         cfg80211_put_dev(rdev);
 961         return res;
 962 }
 963 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 964 #endif