git.oblomov.eu Git - linux-2.6/blob - 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         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  33
  34         if (aborted)
  35                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  36         else
  37                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  38
  39 #ifdef CONFIG_WIRELESS_EXT
  40         if (!aborted) {
  41                 memset(&wrqu, 0, sizeof(wrqu));
  42
  43                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  44         }
  45 #endif
  46
  47         dev_put(dev);
  48
  49  out:
  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                 kref_get(&found->ref);
 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 (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                                         if (ksize(ies) < ielen)
 389                                                 ies = krealloc(ies, ielen,
 390                                                                GFP_ATOMIC);
 391                                 } else
 392                                         ies = kmalloc(ielen, GFP_ATOMIC);
 393
 394                                 if (ies) {
 395                                         memcpy(ies, res->pub.information_elements, ielen);
 396                                         found->ies_allocated = true;
 397                                         found->pub.information_elements = ies;
 398                                         found->pub.len_information_elements = ielen;
 399                                 }
 400                         }
 401                 }
 402
 403                 kref_put(&res->ref, bss_release);
 404         } else {
 405                 /* this "consumes" the reference */
 406                 list_add_tail(&res->list, &dev->bss_list);
 407                 rb_insert_bss(dev, res);
 408                 found = res;
 409         }
 410
 411         dev->bss_generation++;
 412         spin_unlock_bh(&dev->bss_lock);
 413
 414         kref_get(&found->ref);
 415         return found;
 416 }
 417
 418 struct cfg80211_bss*
 419 cfg80211_inform_bss(struct wiphy *wiphy,
 420                     struct ieee80211_channel *channel,
 421                     const u8 *bssid,
 422                     u64 timestamp, u16 capability, u16 beacon_interval,
 423                     const u8 *ie, size_t ielen,
 424                     s32 signal, gfp_t gfp)
 425 {
 426         struct cfg80211_internal_bss *res;
 427         size_t privsz;
 428
 429         if (WARN_ON(!wiphy))
 430                 return NULL;
 431
 432         privsz = wiphy->bss_priv_size;
 433
 434         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 435                         (signal < 0 || signal > 100)))
 436                 return NULL;
 437
 438         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 439         if (!res)
 440                 return NULL;
 441
 442         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 443         res->pub.channel = channel;
 444         res->pub.signal = signal;
 445         res->pub.tsf = timestamp;
 446         res->pub.beacon_interval = beacon_interval;
 447         res->pub.capability = capability;
 448         /* point to after the private area */
 449         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 450         memcpy(res->pub.information_elements, ie, ielen);
 451         res->pub.len_information_elements = ielen;
 452
 453         kref_init(&res->ref);
 454
 455         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 456         if (!res)
 457                 return NULL;
 458
 459         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 460                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 461
 462         /* cfg80211_bss_update gives us a referenced result */
 463         return &res->pub;
 464 }
 465 EXPORT_SYMBOL(cfg80211_inform_bss);
 466
 467 struct cfg80211_bss *
 468 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 469                           struct ieee80211_channel *channel,
 470                           struct ieee80211_mgmt *mgmt, size_t len,
 471                           s32 signal, gfp_t gfp)
 472 {
 473         struct cfg80211_internal_bss *res;
 474         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 475                                       u.probe_resp.variable);
 476         bool overwrite;
 477         size_t privsz = wiphy->bss_priv_size;
 478
 479         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 480                     (signal < 0 || signal > 100)))
 481                 return NULL;
 482
 483         if (WARN_ON(!mgmt || !wiphy ||
 484                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 485                 return NULL;
 486
 487         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 488         if (!res)
 489                 return NULL;
 490
 491         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 492         res->pub.channel = channel;
 493         res->pub.signal = signal;
 494         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 495         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 496         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 497         /* point to after the private area */
 498         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 499         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 500         res->pub.len_information_elements = ielen;
 501
 502         kref_init(&res->ref);
 503
 504         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 505
 506         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 507         if (!res)
 508                 return NULL;
 509
 510         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 511                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 512
 513         /* cfg80211_bss_update gives us a referenced result */
 514         return &res->pub;
 515 }
 516 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 517
 518 void cfg80211_put_bss(struct cfg80211_bss *pub)
 519 {
 520         struct cfg80211_internal_bss *bss;
 521
 522         if (!pub)
 523                 return;
 524
 525         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 526         kref_put(&bss->ref, bss_release);
 527 }
 528 EXPORT_SYMBOL(cfg80211_put_bss);
 529
 530 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 531 {
 532         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 533         struct cfg80211_internal_bss *bss;
 534
 535         if (WARN_ON(!pub))
 536                 return;
 537
 538         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 539
 540         spin_lock_bh(&dev->bss_lock);
 541
 542         list_del(&bss->list);
 543         rb_erase(&bss->rbn, &dev->bss_tree);
 544
 545         spin_unlock_bh(&dev->bss_lock);
 546
 547         kref_put(&bss->ref, bss_release);
 548 }
 549 EXPORT_SYMBOL(cfg80211_unlink_bss);
 550
 551 void cfg80211_hold_bss(struct cfg80211_bss *pub)
 552 {
 553         struct cfg80211_internal_bss *bss;
 554
 555         if (!pub)
 556                 return;
 557
 558         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 559         bss->hold = true;
 560 }
 561 EXPORT_SYMBOL(cfg80211_hold_bss);
 562
 563 void cfg80211_unhold_bss(struct cfg80211_bss *pub)
 564 {
 565         struct cfg80211_internal_bss *bss;
 566
 567         if (!pub)
 568                 return;
 569
 570         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 571         bss->hold = false;
 572 }
 573 EXPORT_SYMBOL(cfg80211_unhold_bss);
 574
 575 #ifdef CONFIG_WIRELESS_EXT
 576 int cfg80211_wext_siwscan(struct net_device *dev,
 577                           struct iw_request_info *info,
 578                           union iwreq_data *wrqu, char *extra)
 579 {
 580         struct cfg80211_registered_device *rdev;
 581         struct wiphy *wiphy;
 582         struct iw_scan_req *wreq = NULL;
 583         struct cfg80211_scan_request *creq;
 584         int i, err, n_channels = 0;
 585         enum ieee80211_band band;
 586
 587         if (!netif_running(dev))
 588                 return -ENETDOWN;
 589
 590         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 591
 592         if (IS_ERR(rdev))
 593                 return PTR_ERR(rdev);
 594
 595         if (rdev->scan_req) {
 596                 err = -EBUSY;
 597                 goto out;
 598         }
 599
 600         wiphy = &rdev->wiphy;
 601
 602         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 603                 if (wiphy->bands[band])
 604                         n_channels += wiphy->bands[band]->n_channels;
 605
 606         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 607                        n_channels * sizeof(void *),
 608                        GFP_ATOMIC);
 609         if (!creq) {
 610                 err = -ENOMEM;
 611                 goto out;
 612         }
 613
 614         creq->wiphy = wiphy;
 615         creq->ifidx = dev->ifindex;
 616         creq->ssids = (void *)(creq + 1);
 617         creq->channels = (void *)(creq->ssids + 1);
 618         creq->n_channels = n_channels;
 619         creq->n_ssids = 1;
 620
 621         /* all channels */
 622         i = 0;
 623         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 624                 int j;
 625                 if (!wiphy->bands[band])
 626                         continue;
 627                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 628                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 629                         i++;
 630                 }
 631         }
 632
 633         /* translate scan request */
 634         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 635                 wreq = (struct iw_scan_req *)extra;
 636
 637                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 638                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 639                                 return -EINVAL;
 640                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 641                         creq->ssids[0].ssid_len = wreq->essid_len;
 642                 }
 643                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 644                         creq->n_ssids = 0;
 645         }
 646
 647         rdev->scan_req = creq;
 648         err = rdev->ops->scan(wiphy, dev, creq);
 649         if (err) {
 650                 rdev->scan_req = NULL;
 651                 kfree(creq);
 652         }
 653  out:
 654         cfg80211_put_dev(rdev);
 655         return err;
 656 }
 657 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 658
 659 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 660                                    struct cfg80211_bss *bss,
 661                                    char **current_ev, char *end_buf)
 662 {
 663         u8 *pos, *end, *next;
 664         struct iw_event iwe;
 665
 666         if (!bss->information_elements ||
 667             !bss->len_information_elements)
 668                 return;
 669
 670         /*
 671          * If needed, fragment the IEs buffer (at IE boundaries) into short
 672          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 673          */
 674         pos = bss->information_elements;
 675         end = pos + bss->len_information_elements;
 676
 677         while (end - pos > IW_GENERIC_IE_MAX) {
 678                 next = pos + 2 + pos[1];
 679                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 680                         next = next + 2 + next[1];
 681
 682                 memset(&iwe, 0, sizeof(iwe));
 683                 iwe.cmd = IWEVGENIE;
 684                 iwe.u.data.length = next - pos;
 685                 *current_ev = iwe_stream_add_point(info, *current_ev,
 686                                                    end_buf, &iwe, pos);
 687
 688                 pos = next;
 689         }
 690
 691         if (end > pos) {
 692                 memset(&iwe, 0, sizeof(iwe));
 693                 iwe.cmd = IWEVGENIE;
 694                 iwe.u.data.length = end - pos;
 695                 *current_ev = iwe_stream_add_point(info, *current_ev,
 696                                                    end_buf, &iwe, pos);
 697         }
 698 }
 699
 700 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 701 {
 702         unsigned long end = jiffies;
 703
 704         if (end >= start)
 705                 return jiffies_to_msecs(end - start);
 706
 707         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 708 }
 709
 710 static char *
 711 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 712               struct cfg80211_internal_bss *bss, char *current_ev,
 713               char *end_buf)
 714 {
 715         struct iw_event iwe;
 716         u8 *buf, *cfg, *p;
 717         u8 *ie = bss->pub.information_elements;
 718         int rem = bss->pub.len_information_elements, i, sig;
 719         bool ismesh = false;
 720
 721         memset(&iwe, 0, sizeof(iwe));
 722         iwe.cmd = SIOCGIWAP;
 723         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 724         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 725         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 726                                           IW_EV_ADDR_LEN);
 727
 728         memset(&iwe, 0, sizeof(iwe));
 729         iwe.cmd = SIOCGIWFREQ;
 730         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 731         iwe.u.freq.e = 0;
 732         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 733                                           IW_EV_FREQ_LEN);
 734
 735         memset(&iwe, 0, sizeof(iwe));
 736         iwe.cmd = SIOCGIWFREQ;
 737         iwe.u.freq.m = bss->pub.channel->center_freq;
 738         iwe.u.freq.e = 6;
 739         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 740                                           IW_EV_FREQ_LEN);
 741
 742         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 743                 memset(&iwe, 0, sizeof(iwe));
 744                 iwe.cmd = IWEVQUAL;
 745                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 746                                      IW_QUAL_NOISE_INVALID |
 747                                      IW_QUAL_QUAL_UPDATED;
 748                 switch (wiphy->signal_type) {
 749                 case CFG80211_SIGNAL_TYPE_MBM:
 750                         sig = bss->pub.signal / 100;
 751                         iwe.u.qual.level = sig;
 752                         iwe.u.qual.updated |= IW_QUAL_DBM;
 753                         if (sig < -110)         /* rather bad */
 754                                 sig = -110;
 755                         else if (sig > -40)     /* perfect */
 756                                 sig = -40;
 757                         /* will give a range of 0 .. 70 */
 758                         iwe.u.qual.qual = sig + 110;
 759                         break;
 760                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 761                         iwe.u.qual.level = bss->pub.signal;
 762                         /* will give range 0 .. 100 */
 763                         iwe.u.qual.qual = bss->pub.signal;
 764                         break;
 765                 default:
 766                         /* not reached */
 767                         break;
 768                 }
 769                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 770                                                   &iwe, IW_EV_QUAL_LEN);
 771         }
 772
 773         memset(&iwe, 0, sizeof(iwe));
 774         iwe.cmd = SIOCGIWENCODE;
 775         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 776                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 777         else
 778                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 779         iwe.u.data.length = 0;
 780         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 781                                           &iwe, "");
 782
 783         while (rem >= 2) {
 784                 /* invalid data */
 785                 if (ie[1] > rem - 2)
 786                         break;
 787
 788                 switch (ie[0]) {
 789                 case WLAN_EID_SSID:
 790                         memset(&iwe, 0, sizeof(iwe));
 791                         iwe.cmd = SIOCGIWESSID;
 792                         iwe.u.data.length = ie[1];
 793                         iwe.u.data.flags = 1;
 794                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 795                                                           &iwe, ie + 2);
 796                         break;
 797                 case WLAN_EID_MESH_ID:
 798                         memset(&iwe, 0, sizeof(iwe));
 799                         iwe.cmd = SIOCGIWESSID;
 800                         iwe.u.data.length = ie[1];
 801                         iwe.u.data.flags = 1;
 802                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 803                                                           &iwe, ie + 2);
 804                         break;
 805                 case WLAN_EID_MESH_CONFIG:
 806                         ismesh = true;
 807                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 808                                 break;
 809                         buf = kmalloc(50, GFP_ATOMIC);
 810                         if (!buf)
 811                                 break;
 812                         cfg = ie + 2;
 813                         memset(&iwe, 0, sizeof(iwe));
 814                         iwe.cmd = IWEVCUSTOM;
 815                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 816                         iwe.u.data.length = strlen(buf);
 817                         current_ev = iwe_stream_add_point(info, current_ev,
 818                                                           end_buf,
 819                                                           &iwe, buf);
 820                         sprintf(buf, "Path Selection Protocol ID: "
 821                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 822                                                         cfg[4]);
 823                         iwe.u.data.length = strlen(buf);
 824                         current_ev = iwe_stream_add_point(info, current_ev,
 825                                                           end_buf,
 826                                                           &iwe, buf);
 827                         sprintf(buf, "Path Selection Metric ID: "
 828                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 829                                                         cfg[8]);
 830                         iwe.u.data.length = strlen(buf);
 831                         current_ev = iwe_stream_add_point(info, current_ev,
 832                                                           end_buf,
 833                                                           &iwe, buf);
 834                         sprintf(buf, "Congestion Control Mode ID: "
 835                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 836                                                         cfg[11], cfg[12]);
 837                         iwe.u.data.length = strlen(buf);
 838                         current_ev = iwe_stream_add_point(info, current_ev,
 839                                                           end_buf,
 840                                                           &iwe, buf);
 841                         sprintf(buf, "Channel Precedence: "
 842                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 843                                                         cfg[15], cfg[16]);
 844                         iwe.u.data.length = strlen(buf);
 845                         current_ev = iwe_stream_add_point(info, current_ev,
 846                                                           end_buf,
 847                                                           &iwe, buf);
 848                         kfree(buf);
 849                         break;
 850                 case WLAN_EID_SUPP_RATES:
 851                 case WLAN_EID_EXT_SUPP_RATES:
 852                         /* display all supported rates in readable format */
 853                         p = current_ev + iwe_stream_lcp_len(info);
 854
 855                         memset(&iwe, 0, sizeof(iwe));
 856                         iwe.cmd = SIOCGIWRATE;
 857                         /* Those two flags are ignored... */
 858                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 859
 860                         for (i = 0; i < ie[1]; i++) {
 861                                 iwe.u.bitrate.value =
 862                                         ((ie[i + 2] & 0x7f) * 500000);
 863                                 p = iwe_stream_add_value(info, current_ev, p,
 864                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 865                         }
 866                         current_ev = p;
 867                         break;
 868                 }
 869                 rem -= ie[1] + 2;
 870                 ie += ie[1] + 2;
 871         }
 872
 873         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 874             || ismesh) {
 875                 memset(&iwe, 0, sizeof(iwe));
 876                 iwe.cmd = SIOCGIWMODE;
 877                 if (ismesh)
 878                         iwe.u.mode = IW_MODE_MESH;
 879                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 880                         iwe.u.mode = IW_MODE_MASTER;
 881                 else
 882                         iwe.u.mode = IW_MODE_ADHOC;
 883                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 884                                                   &iwe, IW_EV_UINT_LEN);
 885         }
 886
 887         buf = kmalloc(30, GFP_ATOMIC);
 888         if (buf) {
 889                 memset(&iwe, 0, sizeof(iwe));
 890                 iwe.cmd = IWEVCUSTOM;
 891                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 892                 iwe.u.data.length = strlen(buf);
 893                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 894                                                   &iwe, buf);
 895                 memset(&iwe, 0, sizeof(iwe));
 896                 iwe.cmd = IWEVCUSTOM;
 897                 sprintf(buf, " Last beacon: %ums ago",
 898                         elapsed_jiffies_msecs(bss->ts));
 899                 iwe.u.data.length = strlen(buf);
 900                 current_ev = iwe_stream_add_point(info, current_ev,
 901                                                   end_buf, &iwe, buf);
 902                 kfree(buf);
 903         }
 904
 905         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 906
 907         return current_ev;
 908 }
 909
 910
 911 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 912                                   struct iw_request_info *info,
 913                                   char *buf, size_t len)
 914 {
 915         char *current_ev = buf;
 916         char *end_buf = buf + len;
 917         struct cfg80211_internal_bss *bss;
 918
 919         spin_lock_bh(&dev->bss_lock);
 920         cfg80211_bss_expire(dev);
 921
 922         list_for_each_entry(bss, &dev->bss_list, list) {
 923                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 924                         spin_unlock_bh(&dev->bss_lock);
 925                         return -E2BIG;
 926                 }
 927                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 928                                            current_ev, end_buf);
 929         }
 930         spin_unlock_bh(&dev->bss_lock);
 931         return current_ev - buf;
 932 }
 933
 934
 935 int cfg80211_wext_giwscan(struct net_device *dev,
 936                           struct iw_request_info *info,
 937                           struct iw_point *data, char *extra)
 938 {
 939         struct cfg80211_registered_device *rdev;
 940         int res;
 941
 942         if (!netif_running(dev))
 943                 return -ENETDOWN;
 944
 945         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 946
 947         if (IS_ERR(rdev))
 948                 return PTR_ERR(rdev);
 949
 950         if (rdev->scan_req) {
 951                 res = -EAGAIN;
 952                 goto out;
 953         }
 954
 955         res = ieee80211_scan_results(rdev, info, extra, data->length);
 956         data->length = 0;
 957         if (res >= 0) {
 958                 data->length = res;
 959                 res = 0;
 960         }
 961
 962  out:
 963         cfg80211_put_dev(rdev);
 964         return res;
 965 }
 966 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 967 #endif