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 work_struct *wk)
  21 {
  22         struct cfg80211_registered_device *rdev;
  23         struct cfg80211_scan_request *request;
  24         struct net_device *dev;
  25 #ifdef CONFIG_WIRELESS_EXT
  26         union iwreq_data wrqu;
  27 #endif
  28
  29         rdev = container_of(wk, struct cfg80211_registered_device,
  30                             scan_done_wk);
  31
  32         mutex_lock(&rdev->mtx);
  33         request = rdev->scan_req;
  34
  35         dev = dev_get_by_index(&init_net, request->ifidx);
  36         if (!dev)
  37                 goto out;
  38
  39         /*
  40          * This must be before sending the other events!
  41          * Otherwise, wpa_supplicant gets completely confused with
  42          * wext events.
  43          */
  44         cfg80211_sme_scan_done(dev);
  45
  46         if (request->aborted)
  47                 nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
  48         else
  49                 nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
  50
  51         wiphy_to_dev(request->wiphy)->scan_req = NULL;
  52
  53 #ifdef CONFIG_WIRELESS_EXT
  54         if (!request->aborted) {
  55                 memset(&wrqu, 0, sizeof(wrqu));
  56
  57                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  58         }
  59 #endif
  60
  61         dev_put(dev);
  62
  63  out:
  64         cfg80211_unlock_rdev(rdev);
  65         kfree(request);
  66 }
  67
  68 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  69 {
  70         struct net_device *dev = dev_get_by_index(&init_net, request->ifidx);
  71         if (WARN_ON(!dev)) {
  72                 kfree(request);
  73                 return;
  74         }
  75
  76         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  77
  78         request->aborted = aborted;
  79         schedule_work(&wiphy_to_dev(request->wiphy)->scan_done_wk);
  80         dev_put(dev);
  81 }
  82 EXPORT_SYMBOL(cfg80211_scan_done);
  83
  84 static void bss_release(struct kref *ref)
  85 {
  86         struct cfg80211_internal_bss *bss;
  87
  88         bss = container_of(ref, struct cfg80211_internal_bss, ref);
  89         if (bss->pub.free_priv)
  90                 bss->pub.free_priv(&bss->pub);
  91
  92         if (bss->ies_allocated)
  93                 kfree(bss->pub.information_elements);
  94
  95         BUG_ON(atomic_read(&bss->hold));
  96
  97         kfree(bss);
  98 }
  99
 100 /* must hold dev->bss_lock! */
 101 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 102                       unsigned long age_secs)
 103 {
 104         struct cfg80211_internal_bss *bss;
 105         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 106
 107         list_for_each_entry(bss, &dev->bss_list, list) {
 108                 bss->ts -= age_jiffies;
 109         }
 110 }
 111
 112 /* must hold dev->bss_lock! */
 113 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 114 {
 115         struct cfg80211_internal_bss *bss, *tmp;
 116         bool expired = false;
 117
 118         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 119                 if (atomic_read(&bss->hold))
 120                         continue;
 121                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 122                         continue;
 123                 list_del(&bss->list);
 124                 rb_erase(&bss->rbn, &dev->bss_tree);
 125                 kref_put(&bss->ref, bss_release);
 126                 expired = true;
 127         }
 128
 129         if (expired)
 130                 dev->bss_generation++;
 131 }
 132
 133 static u8 *find_ie(u8 num, u8 *ies, size_t len)
 134 {
 135         while (len > 2 && ies[0] != num) {
 136                 len -= ies[1] + 2;
 137                 ies += ies[1] + 2;
 138         }
 139         if (len < 2)
 140                 return NULL;
 141         if (len < 2 + ies[1])
 142                 return NULL;
 143         return ies;
 144 }
 145
 146 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 147 {
 148         const u8 *ie1 = find_ie(num, ies1, len1);
 149         const u8 *ie2 = find_ie(num, ies2, len2);
 150         int r;
 151
 152         if (!ie1 && !ie2)
 153                 return 0;
 154         if (!ie1)
 155                 return -1;
 156
 157         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 158         if (r == 0 && ie1[1] != ie2[1])
 159                 return ie2[1] - ie1[1];
 160         return r;
 161 }
 162
 163 static bool is_bss(struct cfg80211_bss *a,
 164                    const u8 *bssid,
 165                    const u8 *ssid, size_t ssid_len)
 166 {
 167         const u8 *ssidie;
 168
 169         if (bssid && compare_ether_addr(a->bssid, bssid))
 170                 return false;
 171
 172         if (!ssid)
 173                 return true;
 174
 175         ssidie = find_ie(WLAN_EID_SSID,
 176                          a->information_elements,
 177                          a->len_information_elements);
 178         if (!ssidie)
 179                 return false;
 180         if (ssidie[1] != ssid_len)
 181                 return false;
 182         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 183 }
 184
 185 static bool is_mesh(struct cfg80211_bss *a,
 186                     const u8 *meshid, size_t meshidlen,
 187                     const u8 *meshcfg)
 188 {
 189         const u8 *ie;
 190
 191         if (!is_zero_ether_addr(a->bssid))
 192                 return false;
 193
 194         ie = find_ie(WLAN_EID_MESH_ID,
 195                      a->information_elements,
 196                      a->len_information_elements);
 197         if (!ie)
 198                 return false;
 199         if (ie[1] != meshidlen)
 200                 return false;
 201         if (memcmp(ie + 2, meshid, meshidlen))
 202                 return false;
 203
 204         ie = find_ie(WLAN_EID_MESH_CONFIG,
 205                      a->information_elements,
 206                      a->len_information_elements);
 207         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 208                 return false;
 209
 210         /*
 211          * Ignore mesh capability (last two bytes of the IE) when
 212          * comparing since that may differ between stations taking
 213          * part in the same mesh.
 214          */
 215         return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
 216 }
 217
 218 static int cmp_bss(struct cfg80211_bss *a,
 219                    struct cfg80211_bss *b)
 220 {
 221         int r;
 222
 223         if (a->channel != b->channel)
 224                 return b->channel->center_freq - a->channel->center_freq;
 225
 226         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 227         if (r)
 228                 return r;
 229
 230         if (is_zero_ether_addr(a->bssid)) {
 231                 r = cmp_ies(WLAN_EID_MESH_ID,
 232                             a->information_elements,
 233                             a->len_information_elements,
 234                             b->information_elements,
 235                             b->len_information_elements);
 236                 if (r)
 237                         return r;
 238                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 239                                a->information_elements,
 240                                a->len_information_elements,
 241                                b->information_elements,
 242                                b->len_information_elements);
 243         }
 244
 245         return cmp_ies(WLAN_EID_SSID,
 246                        a->information_elements,
 247                        a->len_information_elements,
 248                        b->information_elements,
 249                        b->len_information_elements);
 250 }
 251
 252 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 253                                       struct ieee80211_channel *channel,
 254                                       const u8 *bssid,
 255                                       const u8 *ssid, size_t ssid_len,
 256                                       u16 capa_mask, u16 capa_val)
 257 {
 258         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 259         struct cfg80211_internal_bss *bss, *res = NULL;
 260
 261         spin_lock_bh(&dev->bss_lock);
 262
 263         list_for_each_entry(bss, &dev->bss_list, list) {
 264                 if ((bss->pub.capability & capa_mask) != capa_val)
 265                         continue;
 266                 if (channel && bss->pub.channel != channel)
 267                         continue;
 268                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 269                         res = bss;
 270                         kref_get(&res->ref);
 271                         break;
 272                 }
 273         }
 274
 275         spin_unlock_bh(&dev->bss_lock);
 276         if (!res)
 277                 return NULL;
 278         return &res->pub;
 279 }
 280 EXPORT_SYMBOL(cfg80211_get_bss);
 281
 282 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 283                                        struct ieee80211_channel *channel,
 284                                        const u8 *meshid, size_t meshidlen,
 285                                        const u8 *meshcfg)
 286 {
 287         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 288         struct cfg80211_internal_bss *bss, *res = NULL;
 289
 290         spin_lock_bh(&dev->bss_lock);
 291
 292         list_for_each_entry(bss, &dev->bss_list, list) {
 293                 if (channel && bss->pub.channel != channel)
 294                         continue;
 295                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 296                         res = bss;
 297                         kref_get(&res->ref);
 298                         break;
 299                 }
 300         }
 301
 302         spin_unlock_bh(&dev->bss_lock);
 303         if (!res)
 304                 return NULL;
 305         return &res->pub;
 306 }
 307 EXPORT_SYMBOL(cfg80211_get_mesh);
 308
 309
 310 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 311                           struct cfg80211_internal_bss *bss)
 312 {
 313         struct rb_node **p = &dev->bss_tree.rb_node;
 314         struct rb_node *parent = NULL;
 315         struct cfg80211_internal_bss *tbss;
 316         int cmp;
 317
 318         while (*p) {
 319                 parent = *p;
 320                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 321
 322                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 323
 324                 if (WARN_ON(!cmp)) {
 325                         /* will sort of leak this BSS */
 326                         return;
 327                 }
 328
 329                 if (cmp < 0)
 330                         p = &(*p)->rb_left;
 331                 else
 332                         p = &(*p)->rb_right;
 333         }
 334
 335         rb_link_node(&bss->rbn, parent, p);
 336         rb_insert_color(&bss->rbn, &dev->bss_tree);
 337 }
 338
 339 static struct cfg80211_internal_bss *
 340 rb_find_bss(struct cfg80211_registered_device *dev,
 341             struct cfg80211_internal_bss *res)
 342 {
 343         struct rb_node *n = dev->bss_tree.rb_node;
 344         struct cfg80211_internal_bss *bss;
 345         int r;
 346
 347         while (n) {
 348                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 349                 r = cmp_bss(&res->pub, &bss->pub);
 350
 351                 if (r == 0)
 352                         return bss;
 353                 else if (r < 0)
 354                         n = n->rb_left;
 355                 else
 356                         n = n->rb_right;
 357         }
 358
 359         return NULL;
 360 }
 361
 362 static struct cfg80211_internal_bss *
 363 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 364                     struct cfg80211_internal_bss *res,
 365                     bool overwrite)
 366 {
 367         struct cfg80211_internal_bss *found = NULL;
 368         const u8 *meshid, *meshcfg;
 369
 370         /*
 371          * The reference to "res" is donated to this function.
 372          */
 373
 374         if (WARN_ON(!res->pub.channel)) {
 375                 kref_put(&res->ref, bss_release);
 376                 return NULL;
 377         }
 378
 379         res->ts = jiffies;
 380
 381         if (is_zero_ether_addr(res->pub.bssid)) {
 382                 /* must be mesh, verify */
 383                 meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
 384                                  res->pub.len_information_elements);
 385                 meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
 386                                   res->pub.information_elements,
 387                                   res->pub.len_information_elements);
 388                 if (!meshid || !meshcfg ||
 389                     meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
 390                         /* bogus mesh */
 391                         kref_put(&res->ref, bss_release);
 392                         return NULL;
 393                 }
 394         }
 395
 396         spin_lock_bh(&dev->bss_lock);
 397
 398         found = rb_find_bss(dev, res);
 399
 400         if (found) {
 401                 found->pub.beacon_interval = res->pub.beacon_interval;
 402                 found->pub.tsf = res->pub.tsf;
 403                 found->pub.signal = res->pub.signal;
 404                 found->pub.capability = res->pub.capability;
 405                 found->ts = res->ts;
 406
 407                 /* overwrite IEs */
 408                 if (overwrite) {
 409                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 410                         size_t ielen = res->pub.len_information_elements;
 411
 412                         if (!found->ies_allocated && ksize(found) >= used + ielen) {
 413                                 memcpy(found->pub.information_elements,
 414                                        res->pub.information_elements, ielen);
 415                                 found->pub.len_information_elements = ielen;
 416                         } else {
 417                                 u8 *ies = found->pub.information_elements;
 418
 419                                 if (found->ies_allocated)
 420                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 421                                 else
 422                                         ies = kmalloc(ielen, GFP_ATOMIC);
 423
 424                                 if (ies) {
 425                                         memcpy(ies, res->pub.information_elements, ielen);
 426                                         found->ies_allocated = true;
 427                                         found->pub.information_elements = ies;
 428                                         found->pub.len_information_elements = ielen;
 429                                 }
 430                         }
 431                 }
 432
 433                 kref_put(&res->ref, bss_release);
 434         } else {
 435                 /* this "consumes" the reference */
 436                 list_add_tail(&res->list, &dev->bss_list);
 437                 rb_insert_bss(dev, res);
 438                 found = res;
 439         }
 440
 441         dev->bss_generation++;
 442         spin_unlock_bh(&dev->bss_lock);
 443
 444         kref_get(&found->ref);
 445         return found;
 446 }
 447
 448 struct cfg80211_bss*
 449 cfg80211_inform_bss(struct wiphy *wiphy,
 450                     struct ieee80211_channel *channel,
 451                     const u8 *bssid,
 452                     u64 timestamp, u16 capability, u16 beacon_interval,
 453                     const u8 *ie, size_t ielen,
 454                     s32 signal, gfp_t gfp)
 455 {
 456         struct cfg80211_internal_bss *res;
 457         size_t privsz;
 458
 459         if (WARN_ON(!wiphy))
 460                 return NULL;
 461
 462         privsz = wiphy->bss_priv_size;
 463
 464         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 465                         (signal < 0 || signal > 100)))
 466                 return NULL;
 467
 468         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 469         if (!res)
 470                 return NULL;
 471
 472         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 473         res->pub.channel = channel;
 474         res->pub.signal = signal;
 475         res->pub.tsf = timestamp;
 476         res->pub.beacon_interval = beacon_interval;
 477         res->pub.capability = capability;
 478         /* point to after the private area */
 479         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 480         memcpy(res->pub.information_elements, ie, ielen);
 481         res->pub.len_information_elements = ielen;
 482
 483         kref_init(&res->ref);
 484
 485         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
 486         if (!res)
 487                 return NULL;
 488
 489         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 490                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 491
 492         /* cfg80211_bss_update gives us a referenced result */
 493         return &res->pub;
 494 }
 495 EXPORT_SYMBOL(cfg80211_inform_bss);
 496
 497 struct cfg80211_bss *
 498 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 499                           struct ieee80211_channel *channel,
 500                           struct ieee80211_mgmt *mgmt, size_t len,
 501                           s32 signal, gfp_t gfp)
 502 {
 503         struct cfg80211_internal_bss *res;
 504         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 505                                       u.probe_resp.variable);
 506         bool overwrite;
 507         size_t privsz = wiphy->bss_priv_size;
 508
 509         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 510                     (signal < 0 || signal > 100)))
 511                 return NULL;
 512
 513         if (WARN_ON(!mgmt || !wiphy ||
 514                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 515                 return NULL;
 516
 517         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 518         if (!res)
 519                 return NULL;
 520
 521         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 522         res->pub.channel = channel;
 523         res->pub.signal = signal;
 524         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 525         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 526         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 527         /* point to after the private area */
 528         res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
 529         memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
 530         res->pub.len_information_elements = ielen;
 531
 532         kref_init(&res->ref);
 533
 534         overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
 535
 536         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
 537         if (!res)
 538                 return NULL;
 539
 540         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 541                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 542
 543         /* cfg80211_bss_update gives us a referenced result */
 544         return &res->pub;
 545 }
 546 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 547
 548 void cfg80211_put_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         kref_put(&bss->ref, bss_release);
 557 }
 558 EXPORT_SYMBOL(cfg80211_put_bss);
 559
 560 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 561 {
 562         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 563         struct cfg80211_internal_bss *bss;
 564
 565         if (WARN_ON(!pub))
 566                 return;
 567
 568         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 569
 570         spin_lock_bh(&dev->bss_lock);
 571
 572         list_del(&bss->list);
 573         rb_erase(&bss->rbn, &dev->bss_tree);
 574
 575         spin_unlock_bh(&dev->bss_lock);
 576
 577         kref_put(&bss->ref, bss_release);
 578 }
 579 EXPORT_SYMBOL(cfg80211_unlink_bss);
 580
 581 #ifdef CONFIG_WIRELESS_EXT
 582 int cfg80211_wext_siwscan(struct net_device *dev,
 583                           struct iw_request_info *info,
 584                           union iwreq_data *wrqu, char *extra)
 585 {
 586         struct cfg80211_registered_device *rdev;
 587         struct wiphy *wiphy;
 588         struct iw_scan_req *wreq = NULL;
 589         struct cfg80211_scan_request *creq;
 590         int i, err, n_channels = 0;
 591         enum ieee80211_band band;
 592
 593         if (!netif_running(dev))
 594                 return -ENETDOWN;
 595
 596         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 597
 598         if (IS_ERR(rdev))
 599                 return PTR_ERR(rdev);
 600
 601         if (rdev->scan_req) {
 602                 err = -EBUSY;
 603                 goto out;
 604         }
 605
 606         wiphy = &rdev->wiphy;
 607
 608         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 609                 if (wiphy->bands[band])
 610                         n_channels += wiphy->bands[band]->n_channels;
 611
 612         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 613                        n_channels * sizeof(void *),
 614                        GFP_ATOMIC);
 615         if (!creq) {
 616                 err = -ENOMEM;
 617                 goto out;
 618         }
 619
 620         creq->wiphy = wiphy;
 621         creq->ifidx = dev->ifindex;
 622         creq->ssids = (void *)(creq + 1);
 623         creq->channels = (void *)(creq->ssids + 1);
 624         creq->n_channels = n_channels;
 625         creq->n_ssids = 1;
 626
 627         /* all channels */
 628         i = 0;
 629         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 630                 int j;
 631                 if (!wiphy->bands[band])
 632                         continue;
 633                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 634                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 635                         i++;
 636                 }
 637         }
 638
 639         /* translate scan request */
 640         if (wrqu->data.length == sizeof(struct iw_scan_req)) {
 641                 wreq = (struct iw_scan_req *)extra;
 642
 643                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 644                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
 645                                 return -EINVAL;
 646                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 647                         creq->ssids[0].ssid_len = wreq->essid_len;
 648                 }
 649                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 650                         creq->n_ssids = 0;
 651         }
 652
 653         rdev->scan_req = creq;
 654         err = rdev->ops->scan(wiphy, dev, creq);
 655         if (err) {
 656                 rdev->scan_req = NULL;
 657                 kfree(creq);
 658         } else
 659                 nl80211_send_scan_start(rdev, dev);
 660  out:
 661         cfg80211_unlock_rdev(rdev);
 662         return err;
 663 }
 664 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 665
 666 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 667                                    struct cfg80211_bss *bss,
 668                                    char **current_ev, char *end_buf)
 669 {
 670         u8 *pos, *end, *next;
 671         struct iw_event iwe;
 672
 673         if (!bss->information_elements ||
 674             !bss->len_information_elements)
 675                 return;
 676
 677         /*
 678          * If needed, fragment the IEs buffer (at IE boundaries) into short
 679          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 680          */
 681         pos = bss->information_elements;
 682         end = pos + bss->len_information_elements;
 683
 684         while (end - pos > IW_GENERIC_IE_MAX) {
 685                 next = pos + 2 + pos[1];
 686                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 687                         next = next + 2 + next[1];
 688
 689                 memset(&iwe, 0, sizeof(iwe));
 690                 iwe.cmd = IWEVGENIE;
 691                 iwe.u.data.length = next - pos;
 692                 *current_ev = iwe_stream_add_point(info, *current_ev,
 693                                                    end_buf, &iwe, pos);
 694
 695                 pos = next;
 696         }
 697
 698         if (end > pos) {
 699                 memset(&iwe, 0, sizeof(iwe));
 700                 iwe.cmd = IWEVGENIE;
 701                 iwe.u.data.length = end - pos;
 702                 *current_ev = iwe_stream_add_point(info, *current_ev,
 703                                                    end_buf, &iwe, pos);
 704         }
 705 }
 706
 707 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 708 {
 709         unsigned long end = jiffies;
 710
 711         if (end >= start)
 712                 return jiffies_to_msecs(end - start);
 713
 714         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 715 }
 716
 717 static char *
 718 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 719               struct cfg80211_internal_bss *bss, char *current_ev,
 720               char *end_buf)
 721 {
 722         struct iw_event iwe;
 723         u8 *buf, *cfg, *p;
 724         u8 *ie = bss->pub.information_elements;
 725         int rem = bss->pub.len_information_elements, i, sig;
 726         bool ismesh = false;
 727
 728         memset(&iwe, 0, sizeof(iwe));
 729         iwe.cmd = SIOCGIWAP;
 730         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 731         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 732         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 733                                           IW_EV_ADDR_LEN);
 734
 735         memset(&iwe, 0, sizeof(iwe));
 736         iwe.cmd = SIOCGIWFREQ;
 737         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 738         iwe.u.freq.e = 0;
 739         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 740                                           IW_EV_FREQ_LEN);
 741
 742         memset(&iwe, 0, sizeof(iwe));
 743         iwe.cmd = SIOCGIWFREQ;
 744         iwe.u.freq.m = bss->pub.channel->center_freq;
 745         iwe.u.freq.e = 6;
 746         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 747                                           IW_EV_FREQ_LEN);
 748
 749         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 750                 memset(&iwe, 0, sizeof(iwe));
 751                 iwe.cmd = IWEVQUAL;
 752                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 753                                      IW_QUAL_NOISE_INVALID |
 754                                      IW_QUAL_QUAL_UPDATED;
 755                 switch (wiphy->signal_type) {
 756                 case CFG80211_SIGNAL_TYPE_MBM:
 757                         sig = bss->pub.signal / 100;
 758                         iwe.u.qual.level = sig;
 759                         iwe.u.qual.updated |= IW_QUAL_DBM;
 760                         if (sig < -110)         /* rather bad */
 761                                 sig = -110;
 762                         else if (sig > -40)     /* perfect */
 763                                 sig = -40;
 764                         /* will give a range of 0 .. 70 */
 765                         iwe.u.qual.qual = sig + 110;
 766                         break;
 767                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 768                         iwe.u.qual.level = bss->pub.signal;
 769                         /* will give range 0 .. 100 */
 770                         iwe.u.qual.qual = bss->pub.signal;
 771                         break;
 772                 default:
 773                         /* not reached */
 774                         break;
 775                 }
 776                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 777                                                   &iwe, IW_EV_QUAL_LEN);
 778         }
 779
 780         memset(&iwe, 0, sizeof(iwe));
 781         iwe.cmd = SIOCGIWENCODE;
 782         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 783                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 784         else
 785                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 786         iwe.u.data.length = 0;
 787         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 788                                           &iwe, "");
 789
 790         while (rem >= 2) {
 791                 /* invalid data */
 792                 if (ie[1] > rem - 2)
 793                         break;
 794
 795                 switch (ie[0]) {
 796                 case WLAN_EID_SSID:
 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_ID:
 805                         memset(&iwe, 0, sizeof(iwe));
 806                         iwe.cmd = SIOCGIWESSID;
 807                         iwe.u.data.length = ie[1];
 808                         iwe.u.data.flags = 1;
 809                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 810                                                           &iwe, ie + 2);
 811                         break;
 812                 case WLAN_EID_MESH_CONFIG:
 813                         ismesh = true;
 814                         if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
 815                                 break;
 816                         buf = kmalloc(50, GFP_ATOMIC);
 817                         if (!buf)
 818                                 break;
 819                         cfg = ie + 2;
 820                         memset(&iwe, 0, sizeof(iwe));
 821                         iwe.cmd = IWEVCUSTOM;
 822                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 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 Protocol ID: "
 828                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 829                                                         cfg[4]);
 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, "Path Selection Metric ID: "
 835                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 836                                                         cfg[8]);
 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, "Congestion Control Mode ID: "
 842                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 843                                                         cfg[11], cfg[12]);
 844                         iwe.u.data.length = strlen(buf);
 845                         current_ev = iwe_stream_add_point(info, current_ev,
 846                                                           end_buf,
 847                                                           &iwe, buf);
 848                         sprintf(buf, "Channel Precedence: "
 849                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 850                                                         cfg[15], cfg[16]);
 851                         iwe.u.data.length = strlen(buf);
 852                         current_ev = iwe_stream_add_point(info, current_ev,
 853                                                           end_buf,
 854                                                           &iwe, buf);
 855                         kfree(buf);
 856                         break;
 857                 case WLAN_EID_SUPP_RATES:
 858                 case WLAN_EID_EXT_SUPP_RATES:
 859                         /* display all supported rates in readable format */
 860                         p = current_ev + iwe_stream_lcp_len(info);
 861
 862                         memset(&iwe, 0, sizeof(iwe));
 863                         iwe.cmd = SIOCGIWRATE;
 864                         /* Those two flags are ignored... */
 865                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 866
 867                         for (i = 0; i < ie[1]; i++) {
 868                                 iwe.u.bitrate.value =
 869                                         ((ie[i + 2] & 0x7f) * 500000);
 870                                 p = iwe_stream_add_value(info, current_ev, p,
 871                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 872                         }
 873                         current_ev = p;
 874                         break;
 875                 }
 876                 rem -= ie[1] + 2;
 877                 ie += ie[1] + 2;
 878         }
 879
 880         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 881             || ismesh) {
 882                 memset(&iwe, 0, sizeof(iwe));
 883                 iwe.cmd = SIOCGIWMODE;
 884                 if (ismesh)
 885                         iwe.u.mode = IW_MODE_MESH;
 886                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
 887                         iwe.u.mode = IW_MODE_MASTER;
 888                 else
 889                         iwe.u.mode = IW_MODE_ADHOC;
 890                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 891                                                   &iwe, IW_EV_UINT_LEN);
 892         }
 893
 894         buf = kmalloc(30, GFP_ATOMIC);
 895         if (buf) {
 896                 memset(&iwe, 0, sizeof(iwe));
 897                 iwe.cmd = IWEVCUSTOM;
 898                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
 899                 iwe.u.data.length = strlen(buf);
 900                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 901                                                   &iwe, buf);
 902                 memset(&iwe, 0, sizeof(iwe));
 903                 iwe.cmd = IWEVCUSTOM;
 904                 sprintf(buf, " Last beacon: %ums ago",
 905                         elapsed_jiffies_msecs(bss->ts));
 906                 iwe.u.data.length = strlen(buf);
 907                 current_ev = iwe_stream_add_point(info, current_ev,
 908                                                   end_buf, &iwe, buf);
 909                 kfree(buf);
 910         }
 911
 912         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
 913
 914         return current_ev;
 915 }
 916
 917
 918 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
 919                                   struct iw_request_info *info,
 920                                   char *buf, size_t len)
 921 {
 922         char *current_ev = buf;
 923         char *end_buf = buf + len;
 924         struct cfg80211_internal_bss *bss;
 925
 926         spin_lock_bh(&dev->bss_lock);
 927         cfg80211_bss_expire(dev);
 928
 929         list_for_each_entry(bss, &dev->bss_list, list) {
 930                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 931                         spin_unlock_bh(&dev->bss_lock);
 932                         return -E2BIG;
 933                 }
 934                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
 935                                            current_ev, end_buf);
 936         }
 937         spin_unlock_bh(&dev->bss_lock);
 938         return current_ev - buf;
 939 }
 940
 941
 942 int cfg80211_wext_giwscan(struct net_device *dev,
 943                           struct iw_request_info *info,
 944                           struct iw_point *data, char *extra)
 945 {
 946         struct cfg80211_registered_device *rdev;
 947         int res;
 948
 949         if (!netif_running(dev))
 950                 return -ENETDOWN;
 951
 952         rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
 953
 954         if (IS_ERR(rdev))
 955                 return PTR_ERR(rdev);
 956
 957         if (rdev->scan_req) {
 958                 res = -EAGAIN;
 959                 goto out;
 960         }
 961
 962         res = ieee80211_scan_results(rdev, info, extra, data->length);
 963         data->length = 0;
 964         if (res >= 0) {
 965                 data->length = res;
 966                 res = 0;
 967         }
 968
 969  out:
 970         cfg80211_unlock_rdev(rdev);
 971         return res;
 972 }
 973 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
 974 #endif