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