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 #include "wext-compat.h"
  18
  19 #define IEEE80211_SCAN_RESULT_EXPIRE    (15 * HZ)
  20
  21 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
  22 {
  23         struct cfg80211_scan_request *request;
  24         struct net_device *dev;
  25 #ifdef CONFIG_CFG80211_WEXT
  26         union iwreq_data wrqu;
  27 #endif
  28
  29         ASSERT_RDEV_LOCK(rdev);
  30
  31         request = rdev->scan_req;
  32
  33         if (!request)
  34                 return;
  35
  36         dev = request->dev;
  37
  38         /*
  39          * This must be before sending the other events!
  40          * Otherwise, wpa_supplicant gets completely confused with
  41          * wext events.
  42          */
  43         cfg80211_sme_scan_done(dev);
  44
  45         if (request->aborted)
  46                 nl80211_send_scan_aborted(rdev, dev);
  47         else
  48                 nl80211_send_scan_done(rdev, dev);
  49
  50 #ifdef CONFIG_CFG80211_WEXT
  51         if (!request->aborted) {
  52                 memset(&wrqu, 0, sizeof(wrqu));
  53
  54                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
  55         }
  56 #endif
  57
  58         dev_put(dev);
  59
  60         rdev->scan_req = NULL;
  61
  62         /*
  63          * OK. If this is invoked with "leak" then we can't
  64          * free this ... but we've cleaned it up anyway. The
  65          * driver failed to call the scan_done callback, so
  66          * all bets are off, it might still be trying to use
  67          * the scan request or not ... if it accesses the dev
  68          * in there (it shouldn't anyway) then it may crash.
  69          */
  70         if (!leak)
  71                 kfree(request);
  72 }
  73
  74 void __cfg80211_scan_done(struct work_struct *wk)
  75 {
  76         struct cfg80211_registered_device *rdev;
  77
  78         rdev = container_of(wk, struct cfg80211_registered_device,
  79                             scan_done_wk);
  80
  81         cfg80211_lock_rdev(rdev);
  82         ___cfg80211_scan_done(rdev, false);
  83         cfg80211_unlock_rdev(rdev);
  84 }
  85
  86 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
  87 {
  88         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
  89
  90         request->aborted = aborted;
  91         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
  92 }
  93 EXPORT_SYMBOL(cfg80211_scan_done);
  94
  95 static void bss_release(struct kref *ref)
  96 {
  97         struct cfg80211_internal_bss *bss;
  98
  99         bss = container_of(ref, struct cfg80211_internal_bss, ref);
 100         if (bss->pub.free_priv)
 101                 bss->pub.free_priv(&bss->pub);
 102
 103         if (bss->beacon_ies_allocated)
 104                 kfree(bss->pub.beacon_ies);
 105         if (bss->proberesp_ies_allocated)
 106                 kfree(bss->pub.proberesp_ies);
 107
 108         BUG_ON(atomic_read(&bss->hold));
 109
 110         kfree(bss);
 111 }
 112
 113 /* must hold dev->bss_lock! */
 114 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 115                       unsigned long age_secs)
 116 {
 117         struct cfg80211_internal_bss *bss;
 118         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 119
 120         list_for_each_entry(bss, &dev->bss_list, list) {
 121                 bss->ts -= age_jiffies;
 122         }
 123 }
 124
 125 /* must hold dev->bss_lock! */
 126 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 127 {
 128         struct cfg80211_internal_bss *bss, *tmp;
 129         bool expired = false;
 130
 131         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 132                 if (atomic_read(&bss->hold))
 133                         continue;
 134                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
 135                         continue;
 136                 list_del(&bss->list);
 137                 rb_erase(&bss->rbn, &dev->bss_tree);
 138                 kref_put(&bss->ref, bss_release);
 139                 expired = true;
 140         }
 141
 142         if (expired)
 143                 dev->bss_generation++;
 144 }
 145
 146 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 147 {
 148         while (len > 2 && ies[0] != eid) {
 149                 len -= ies[1] + 2;
 150                 ies += ies[1] + 2;
 151         }
 152         if (len < 2)
 153                 return NULL;
 154         if (len < 2 + ies[1])
 155                 return NULL;
 156         return ies;
 157 }
 158 EXPORT_SYMBOL(cfg80211_find_ie);
 159
 160 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
 161 {
 162         const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
 163         const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
 164         int r;
 165
 166         if (!ie1 && !ie2)
 167                 return 0;
 168         if (!ie1 || !ie2)
 169                 return -1;
 170
 171         r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
 172         if (r == 0 && ie1[1] != ie2[1])
 173                 return ie2[1] - ie1[1];
 174         return r;
 175 }
 176
 177 static bool is_bss(struct cfg80211_bss *a,
 178                    const u8 *bssid,
 179                    const u8 *ssid, size_t ssid_len)
 180 {
 181         const u8 *ssidie;
 182
 183         if (bssid && compare_ether_addr(a->bssid, bssid))
 184                 return false;
 185
 186         if (!ssid)
 187                 return true;
 188
 189         ssidie = cfg80211_find_ie(WLAN_EID_SSID,
 190                                   a->information_elements,
 191                                   a->len_information_elements);
 192         if (!ssidie)
 193                 return false;
 194         if (ssidie[1] != ssid_len)
 195                 return false;
 196         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 197 }
 198
 199 static bool is_mesh(struct cfg80211_bss *a,
 200                     const u8 *meshid, size_t meshidlen,
 201                     const u8 *meshcfg)
 202 {
 203         const u8 *ie;
 204
 205         if (!is_zero_ether_addr(a->bssid))
 206                 return false;
 207
 208         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
 209                               a->information_elements,
 210                               a->len_information_elements);
 211         if (!ie)
 212                 return false;
 213         if (ie[1] != meshidlen)
 214                 return false;
 215         if (memcmp(ie + 2, meshid, meshidlen))
 216                 return false;
 217
 218         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 219                               a->information_elements,
 220                               a->len_information_elements);
 221         if (!ie)
 222                 return false;
 223         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 224                 return false;
 225
 226         /*
 227          * Ignore mesh capability (last two bytes of the IE) when
 228          * comparing since that may differ between stations taking
 229          * part in the same mesh.
 230          */
 231         return memcmp(ie + 2, meshcfg,
 232             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
 233 }
 234
 235 static int cmp_bss(struct cfg80211_bss *a,
 236                    struct cfg80211_bss *b)
 237 {
 238         int r;
 239
 240         if (a->channel != b->channel)
 241                 return b->channel->center_freq - a->channel->center_freq;
 242
 243         r = memcmp(a->bssid, b->bssid, ETH_ALEN);
 244         if (r)
 245                 return r;
 246
 247         if (is_zero_ether_addr(a->bssid)) {
 248                 r = cmp_ies(WLAN_EID_MESH_ID,
 249                             a->information_elements,
 250                             a->len_information_elements,
 251                             b->information_elements,
 252                             b->len_information_elements);
 253                 if (r)
 254                         return r;
 255                 return cmp_ies(WLAN_EID_MESH_CONFIG,
 256                                a->information_elements,
 257                                a->len_information_elements,
 258                                b->information_elements,
 259                                b->len_information_elements);
 260         }
 261
 262         return cmp_ies(WLAN_EID_SSID,
 263                        a->information_elements,
 264                        a->len_information_elements,
 265                        b->information_elements,
 266                        b->len_information_elements);
 267 }
 268
 269 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 270                                       struct ieee80211_channel *channel,
 271                                       const u8 *bssid,
 272                                       const u8 *ssid, size_t ssid_len,
 273                                       u16 capa_mask, u16 capa_val)
 274 {
 275         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 276         struct cfg80211_internal_bss *bss, *res = NULL;
 277
 278         spin_lock_bh(&dev->bss_lock);
 279
 280         list_for_each_entry(bss, &dev->bss_list, list) {
 281                 if ((bss->pub.capability & capa_mask) != capa_val)
 282                         continue;
 283                 if (channel && bss->pub.channel != channel)
 284                         continue;
 285                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 286                         res = bss;
 287                         kref_get(&res->ref);
 288                         break;
 289                 }
 290         }
 291
 292         spin_unlock_bh(&dev->bss_lock);
 293         if (!res)
 294                 return NULL;
 295         return &res->pub;
 296 }
 297 EXPORT_SYMBOL(cfg80211_get_bss);
 298
 299 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 300                                        struct ieee80211_channel *channel,
 301                                        const u8 *meshid, size_t meshidlen,
 302                                        const u8 *meshcfg)
 303 {
 304         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 305         struct cfg80211_internal_bss *bss, *res = NULL;
 306
 307         spin_lock_bh(&dev->bss_lock);
 308
 309         list_for_each_entry(bss, &dev->bss_list, list) {
 310                 if (channel && bss->pub.channel != channel)
 311                         continue;
 312                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
 313                         res = bss;
 314                         kref_get(&res->ref);
 315                         break;
 316                 }
 317         }
 318
 319         spin_unlock_bh(&dev->bss_lock);
 320         if (!res)
 321                 return NULL;
 322         return &res->pub;
 323 }
 324 EXPORT_SYMBOL(cfg80211_get_mesh);
 325
 326
 327 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 328                           struct cfg80211_internal_bss *bss)
 329 {
 330         struct rb_node **p = &dev->bss_tree.rb_node;
 331         struct rb_node *parent = NULL;
 332         struct cfg80211_internal_bss *tbss;
 333         int cmp;
 334
 335         while (*p) {
 336                 parent = *p;
 337                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 338
 339                 cmp = cmp_bss(&bss->pub, &tbss->pub);
 340
 341                 if (WARN_ON(!cmp)) {
 342                         /* will sort of leak this BSS */
 343                         return;
 344                 }
 345
 346                 if (cmp < 0)
 347                         p = &(*p)->rb_left;
 348                 else
 349                         p = &(*p)->rb_right;
 350         }
 351
 352         rb_link_node(&bss->rbn, parent, p);
 353         rb_insert_color(&bss->rbn, &dev->bss_tree);
 354 }
 355
 356 static struct cfg80211_internal_bss *
 357 rb_find_bss(struct cfg80211_registered_device *dev,
 358             struct cfg80211_internal_bss *res)
 359 {
 360         struct rb_node *n = dev->bss_tree.rb_node;
 361         struct cfg80211_internal_bss *bss;
 362         int r;
 363
 364         while (n) {
 365                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 366                 r = cmp_bss(&res->pub, &bss->pub);
 367
 368                 if (r == 0)
 369                         return bss;
 370                 else if (r < 0)
 371                         n = n->rb_left;
 372                 else
 373                         n = n->rb_right;
 374         }
 375
 376         return NULL;
 377 }
 378
 379 static struct cfg80211_internal_bss *
 380 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 381                     struct cfg80211_internal_bss *res)
 382 {
 383         struct cfg80211_internal_bss *found = NULL;
 384         const u8 *meshid, *meshcfg;
 385
 386         /*
 387          * The reference to "res" is donated to this function.
 388          */
 389
 390         if (WARN_ON(!res->pub.channel)) {
 391                 kref_put(&res->ref, bss_release);
 392                 return NULL;
 393         }
 394
 395         res->ts = jiffies;
 396
 397         if (is_zero_ether_addr(res->pub.bssid)) {
 398                 /* must be mesh, verify */
 399                 meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
 400                                           res->pub.information_elements,
 401                                           res->pub.len_information_elements);
 402                 meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 403                                            res->pub.information_elements,
 404                                            res->pub.len_information_elements);
 405                 if (!meshid || !meshcfg ||
 406                     meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
 407                         /* bogus mesh */
 408                         kref_put(&res->ref, bss_release);
 409                         return NULL;
 410                 }
 411         }
 412
 413         spin_lock_bh(&dev->bss_lock);
 414
 415         found = rb_find_bss(dev, res);
 416
 417         if (found) {
 418                 found->pub.beacon_interval = res->pub.beacon_interval;
 419                 found->pub.tsf = res->pub.tsf;
 420                 found->pub.signal = res->pub.signal;
 421                 found->pub.capability = res->pub.capability;
 422                 found->ts = res->ts;
 423
 424                 /* Update IEs */
 425                 if (res->pub.proberesp_ies) {
 426                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 427                         size_t ielen = res->pub.len_proberesp_ies;
 428
 429                         if (found->pub.proberesp_ies &&
 430                             !found->proberesp_ies_allocated &&
 431                             ksize(found) >= used + ielen) {
 432                                 memcpy(found->pub.proberesp_ies,
 433                                        res->pub.proberesp_ies, ielen);
 434                                 found->pub.len_proberesp_ies = ielen;
 435                         } else {
 436                                 u8 *ies = found->pub.proberesp_ies;
 437
 438                                 if (found->proberesp_ies_allocated)
 439                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 440                                 else
 441                                         ies = kmalloc(ielen, GFP_ATOMIC);
 442
 443                                 if (ies) {
 444                                         memcpy(ies, res->pub.proberesp_ies,
 445                                                ielen);
 446                                         found->proberesp_ies_allocated = true;
 447                                         found->pub.proberesp_ies = ies;
 448                                         found->pub.len_proberesp_ies = ielen;
 449                                 }
 450                         }
 451
 452                         /* Override possible earlier Beacon frame IEs */
 453                         found->pub.information_elements =
 454                                 found->pub.proberesp_ies;
 455                         found->pub.len_information_elements =
 456                                 found->pub.len_proberesp_ies;
 457                 }
 458                 if (res->pub.beacon_ies) {
 459                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
 460                         size_t ielen = res->pub.len_beacon_ies;
 461
 462                         if (found->pub.beacon_ies &&
 463                             !found->beacon_ies_allocated &&
 464                             ksize(found) >= used + ielen) {
 465                                 memcpy(found->pub.beacon_ies,
 466                                        res->pub.beacon_ies, ielen);
 467                                 found->pub.len_beacon_ies = ielen;
 468                         } else {
 469                                 u8 *ies = found->pub.beacon_ies;
 470
 471                                 if (found->beacon_ies_allocated)
 472                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
 473                                 else
 474                                         ies = kmalloc(ielen, GFP_ATOMIC);
 475
 476                                 if (ies) {
 477                                         memcpy(ies, res->pub.beacon_ies,
 478                                                ielen);
 479                                         found->beacon_ies_allocated = true;
 480                                         found->pub.beacon_ies = ies;
 481                                         found->pub.len_beacon_ies = ielen;
 482                                 }
 483                         }
 484                 }
 485
 486                 kref_put(&res->ref, bss_release);
 487         } else {
 488                 /* this "consumes" the reference */
 489                 list_add_tail(&res->list, &dev->bss_list);
 490                 rb_insert_bss(dev, res);
 491                 found = res;
 492         }
 493
 494         dev->bss_generation++;
 495         spin_unlock_bh(&dev->bss_lock);
 496
 497         kref_get(&found->ref);
 498         return found;
 499 }
 500
 501 struct cfg80211_bss*
 502 cfg80211_inform_bss(struct wiphy *wiphy,
 503                     struct ieee80211_channel *channel,
 504                     const u8 *bssid,
 505                     u64 timestamp, u16 capability, u16 beacon_interval,
 506                     const u8 *ie, size_t ielen,
 507                     s32 signal, gfp_t gfp)
 508 {
 509         struct cfg80211_internal_bss *res;
 510         size_t privsz;
 511
 512         if (WARN_ON(!wiphy))
 513                 return NULL;
 514
 515         privsz = wiphy->bss_priv_size;
 516
 517         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 518                         (signal < 0 || signal > 100)))
 519                 return NULL;
 520
 521         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 522         if (!res)
 523                 return NULL;
 524
 525         memcpy(res->pub.bssid, bssid, ETH_ALEN);
 526         res->pub.channel = channel;
 527         res->pub.signal = signal;
 528         res->pub.tsf = timestamp;
 529         res->pub.beacon_interval = beacon_interval;
 530         res->pub.capability = capability;
 531         /*
 532          * Since we do not know here whether the IEs are from a Beacon or Probe
 533          * Response frame, we need to pick one of the options and only use it
 534          * with the driver that does not provide the full Beacon/Probe Response
 535          * frame. Use Beacon frame pointer to avoid indicating that this should
 536          * override the information_elements pointer should we have received an
 537          * earlier indication of Probe Response data.
 538          *
 539          * The initial buffer for the IEs is allocated with the BSS entry and
 540          * is located after the private area.
 541          */
 542         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
 543         memcpy(res->pub.beacon_ies, ie, ielen);
 544         res->pub.len_beacon_ies = ielen;
 545         res->pub.information_elements = res->pub.beacon_ies;
 546         res->pub.len_information_elements = res->pub.len_beacon_ies;
 547
 548         kref_init(&res->ref);
 549
 550         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 551         if (!res)
 552                 return NULL;
 553
 554         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 555                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 556
 557         /* cfg80211_bss_update gives us a referenced result */
 558         return &res->pub;
 559 }
 560 EXPORT_SYMBOL(cfg80211_inform_bss);
 561
 562 struct cfg80211_bss *
 563 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 564                           struct ieee80211_channel *channel,
 565                           struct ieee80211_mgmt *mgmt, size_t len,
 566                           s32 signal, gfp_t gfp)
 567 {
 568         struct cfg80211_internal_bss *res;
 569         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 570                                       u.probe_resp.variable);
 571         size_t privsz = wiphy->bss_priv_size;
 572
 573         if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
 574                     (signal < 0 || signal > 100)))
 575                 return NULL;
 576
 577         if (WARN_ON(!mgmt || !wiphy ||
 578                     len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 579                 return NULL;
 580
 581         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
 582         if (!res)
 583                 return NULL;
 584
 585         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
 586         res->pub.channel = channel;
 587         res->pub.signal = signal;
 588         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 589         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 590         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 591         /*
 592          * The initial buffer for the IEs is allocated with the BSS entry and
 593          * is located after the private area.
 594          */
 595         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 596                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
 597                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
 598                        ielen);
 599                 res->pub.len_proberesp_ies = ielen;
 600                 res->pub.information_elements = res->pub.proberesp_ies;
 601                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
 602         } else {
 603                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
 604                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
 605                 res->pub.len_beacon_ies = ielen;
 606                 res->pub.information_elements = res->pub.beacon_ies;
 607                 res->pub.len_information_elements = res->pub.len_beacon_ies;
 608         }
 609
 610         kref_init(&res->ref);
 611
 612         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
 613         if (!res)
 614                 return NULL;
 615
 616         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 617                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 618
 619         /* cfg80211_bss_update gives us a referenced result */
 620         return &res->pub;
 621 }
 622 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 623
 624 void cfg80211_put_bss(struct cfg80211_bss *pub)
 625 {
 626         struct cfg80211_internal_bss *bss;
 627
 628         if (!pub)
 629                 return;
 630
 631         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 632         kref_put(&bss->ref, bss_release);
 633 }
 634 EXPORT_SYMBOL(cfg80211_put_bss);
 635
 636 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 637 {
 638         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 639         struct cfg80211_internal_bss *bss;
 640
 641         if (WARN_ON(!pub))
 642                 return;
 643
 644         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 645
 646         spin_lock_bh(&dev->bss_lock);
 647
 648         list_del(&bss->list);
 649         dev->bss_generation++;
 650         rb_erase(&bss->rbn, &dev->bss_tree);
 651
 652         spin_unlock_bh(&dev->bss_lock);
 653
 654         kref_put(&bss->ref, bss_release);
 655 }
 656 EXPORT_SYMBOL(cfg80211_unlink_bss);
 657
 658 #ifdef CONFIG_CFG80211_WEXT
 659 int cfg80211_wext_siwscan(struct net_device *dev,
 660                           struct iw_request_info *info,
 661                           union iwreq_data *wrqu, char *extra)
 662 {
 663         struct cfg80211_registered_device *rdev;
 664         struct wiphy *wiphy;
 665         struct iw_scan_req *wreq = NULL;
 666         struct cfg80211_scan_request *creq = NULL;
 667         int i, err, n_channels = 0;
 668         enum ieee80211_band band;
 669
 670         if (!netif_running(dev))
 671                 return -ENETDOWN;
 672
 673         if (wrqu->data.length == sizeof(struct iw_scan_req))
 674                 wreq = (struct iw_scan_req *)extra;
 675
 676         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
 677
 678         if (IS_ERR(rdev))
 679                 return PTR_ERR(rdev);
 680
 681         if (rdev->scan_req) {
 682                 err = -EBUSY;
 683                 goto out;
 684         }
 685
 686         wiphy = &rdev->wiphy;
 687
 688         /* Determine number of channels, needed to allocate creq */
 689         if (wreq && wreq->num_channels)
 690                 n_channels = wreq->num_channels;
 691         else {
 692                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 693                         if (wiphy->bands[band])
 694                                 n_channels += wiphy->bands[band]->n_channels;
 695         }
 696
 697         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 698                        n_channels * sizeof(void *),
 699                        GFP_ATOMIC);
 700         if (!creq) {
 701                 err = -ENOMEM;
 702                 goto out;
 703         }
 704
 705         creq->wiphy = wiphy;
 706         creq->dev = dev;
 707         /* SSIDs come after channels */
 708         creq->ssids = (void *)&creq->channels[n_channels];
 709         creq->n_channels = n_channels;
 710         creq->n_ssids = 1;
 711
 712         /* translate "Scan on frequencies" request */
 713         i = 0;
 714         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 715                 int j;
 716
 717                 if (!wiphy->bands[band])
 718                         continue;
 719
 720                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
 721                         /* ignore disabled channels */
 722                         if (wiphy->bands[band]->channels[j].flags &
 723                                                 IEEE80211_CHAN_DISABLED)
 724                                 continue;
 725
 726                         /* If we have a wireless request structure and the
 727                          * wireless request specifies frequencies, then search
 728                          * for the matching hardware channel.
 729                          */
 730                         if (wreq && wreq->num_channels) {
 731                                 int k;
 732                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
 733                                 for (k = 0; k < wreq->num_channels; k++) {
 734                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
 735                                         if (wext_freq == wiphy_freq)
 736                                                 goto wext_freq_found;
 737                                 }
 738                                 goto wext_freq_not_found;
 739                         }
 740
 741                 wext_freq_found:
 742                         creq->channels[i] = &wiphy->bands[band]->channels[j];
 743                         i++;
 744                 wext_freq_not_found: ;
 745                 }
 746         }
 747         /* No channels found? */
 748         if (!i) {
 749                 err = -EINVAL;
 750                 goto out;
 751         }
 752
 753         /* Set real number of channels specified in creq->channels[] */
 754         creq->n_channels = i;
 755
 756         /* translate "Scan for SSID" request */
 757         if (wreq) {
 758                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 759                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
 760                                 err = -EINVAL;
 761                                 goto out;
 762                         }
 763                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
 764                         creq->ssids[0].ssid_len = wreq->essid_len;
 765                 }
 766                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
 767                         creq->n_ssids = 0;
 768         }
 769
 770         rdev->scan_req = creq;
 771         err = rdev->ops->scan(wiphy, dev, creq);
 772         if (err) {
 773                 rdev->scan_req = NULL;
 774                 /* creq will be freed below */
 775         } else {
 776                 nl80211_send_scan_start(rdev, dev);
 777                 /* creq now owned by driver */
 778                 creq = NULL;
 779                 dev_hold(dev);
 780         }
 781  out:
 782         kfree(creq);
 783         cfg80211_unlock_rdev(rdev);
 784         return err;
 785 }
 786 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
 787
 788 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 789                                    struct cfg80211_bss *bss,
 790                                    char **current_ev, char *end_buf)
 791 {
 792         u8 *pos, *end, *next;
 793         struct iw_event iwe;
 794
 795         if (!bss->information_elements ||
 796             !bss->len_information_elements)
 797                 return;
 798
 799         /*
 800          * If needed, fragment the IEs buffer (at IE boundaries) into short
 801          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 802          */
 803         pos = bss->information_elements;
 804         end = pos + bss->len_information_elements;
 805
 806         while (end - pos > IW_GENERIC_IE_MAX) {
 807                 next = pos + 2 + pos[1];
 808                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 809                         next = next + 2 + next[1];
 810
 811                 memset(&iwe, 0, sizeof(iwe));
 812                 iwe.cmd = IWEVGENIE;
 813                 iwe.u.data.length = next - pos;
 814                 *current_ev = iwe_stream_add_point(info, *current_ev,
 815                                                    end_buf, &iwe, pos);
 816
 817                 pos = next;
 818         }
 819
 820         if (end > pos) {
 821                 memset(&iwe, 0, sizeof(iwe));
 822                 iwe.cmd = IWEVGENIE;
 823                 iwe.u.data.length = end - pos;
 824                 *current_ev = iwe_stream_add_point(info, *current_ev,
 825                                                    end_buf, &iwe, pos);
 826         }
 827 }
 828
 829 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 830 {
 831         unsigned long end = jiffies;
 832
 833         if (end >= start)
 834                 return jiffies_to_msecs(end - start);
 835
 836         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
 837 }
 838
 839 static char *
 840 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 841               struct cfg80211_internal_bss *bss, char *current_ev,
 842               char *end_buf)
 843 {
 844         struct iw_event iwe;
 845         u8 *buf, *cfg, *p;
 846         u8 *ie = bss->pub.information_elements;
 847         int rem = bss->pub.len_information_elements, i, sig;
 848         bool ismesh = false;
 849
 850         memset(&iwe, 0, sizeof(iwe));
 851         iwe.cmd = SIOCGIWAP;
 852         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 853         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
 854         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 855                                           IW_EV_ADDR_LEN);
 856
 857         memset(&iwe, 0, sizeof(iwe));
 858         iwe.cmd = SIOCGIWFREQ;
 859         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
 860         iwe.u.freq.e = 0;
 861         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 862                                           IW_EV_FREQ_LEN);
 863
 864         memset(&iwe, 0, sizeof(iwe));
 865         iwe.cmd = SIOCGIWFREQ;
 866         iwe.u.freq.m = bss->pub.channel->center_freq;
 867         iwe.u.freq.e = 6;
 868         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 869                                           IW_EV_FREQ_LEN);
 870
 871         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
 872                 memset(&iwe, 0, sizeof(iwe));
 873                 iwe.cmd = IWEVQUAL;
 874                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
 875                                      IW_QUAL_NOISE_INVALID |
 876                                      IW_QUAL_QUAL_UPDATED;
 877                 switch (wiphy->signal_type) {
 878                 case CFG80211_SIGNAL_TYPE_MBM:
 879                         sig = bss->pub.signal / 100;
 880                         iwe.u.qual.level = sig;
 881                         iwe.u.qual.updated |= IW_QUAL_DBM;
 882                         if (sig < -110)         /* rather bad */
 883                                 sig = -110;
 884                         else if (sig > -40)     /* perfect */
 885                                 sig = -40;
 886                         /* will give a range of 0 .. 70 */
 887                         iwe.u.qual.qual = sig + 110;
 888                         break;
 889                 case CFG80211_SIGNAL_TYPE_UNSPEC:
 890                         iwe.u.qual.level = bss->pub.signal;
 891                         /* will give range 0 .. 100 */
 892                         iwe.u.qual.qual = bss->pub.signal;
 893                         break;
 894                 default:
 895                         /* not reached */
 896                         break;
 897                 }
 898                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 899                                                   &iwe, IW_EV_QUAL_LEN);
 900         }
 901
 902         memset(&iwe, 0, sizeof(iwe));
 903         iwe.cmd = SIOCGIWENCODE;
 904         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
 905                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 906         else
 907                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 908         iwe.u.data.length = 0;
 909         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 910                                           &iwe, "");
 911
 912         while (rem >= 2) {
 913                 /* invalid data */
 914                 if (ie[1] > rem - 2)
 915                         break;
 916
 917                 switch (ie[0]) {
 918                 case WLAN_EID_SSID:
 919                         memset(&iwe, 0, sizeof(iwe));
 920                         iwe.cmd = SIOCGIWESSID;
 921                         iwe.u.data.length = ie[1];
 922                         iwe.u.data.flags = 1;
 923                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 924                                                           &iwe, ie + 2);
 925                         break;
 926                 case WLAN_EID_MESH_ID:
 927                         memset(&iwe, 0, sizeof(iwe));
 928                         iwe.cmd = SIOCGIWESSID;
 929                         iwe.u.data.length = ie[1];
 930                         iwe.u.data.flags = 1;
 931                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 932                                                           &iwe, ie + 2);
 933                         break;
 934                 case WLAN_EID_MESH_CONFIG:
 935                         ismesh = true;
 936                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
 937                                 break;
 938                         buf = kmalloc(50, GFP_ATOMIC);
 939                         if (!buf)
 940                                 break;
 941                         cfg = ie + 2;
 942                         memset(&iwe, 0, sizeof(iwe));
 943                         iwe.cmd = IWEVCUSTOM;
 944                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
 945                                 "0x%02X", cfg[0]);
 946                         iwe.u.data.length = strlen(buf);
 947                         current_ev = iwe_stream_add_point(info, current_ev,
 948                                                           end_buf,
 949                                                           &iwe, buf);
 950                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
 951                                 cfg[1]);
 952                         iwe.u.data.length = strlen(buf);
 953                         current_ev = iwe_stream_add_point(info, current_ev,
 954                                                           end_buf,
 955                                                           &iwe, buf);
 956                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
 957                                 cfg[2]);
 958                         iwe.u.data.length = strlen(buf);
 959                         current_ev = iwe_stream_add_point(info, current_ev,
 960                                                           end_buf,
 961                                                           &iwe, buf);
 962                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
 963                         iwe.u.data.length = strlen(buf);
 964                         current_ev = iwe_stream_add_point(info, current_ev,
 965                                                           end_buf,
 966                                                           &iwe, buf);
 967                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
 968                         iwe.u.data.length = strlen(buf);
 969                         current_ev = iwe_stream_add_point(info, current_ev,
 970                                                           end_buf,
 971                                                           &iwe, buf);
 972                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
 973                         iwe.u.data.length = strlen(buf);
 974                         current_ev = iwe_stream_add_point(info, current_ev,
 975                                                           end_buf,
 976                                                           &iwe, buf);
 977                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
 978                         iwe.u.data.length = strlen(buf);
 979                         current_ev = iwe_stream_add_point(info, current_ev,
 980                                                           end_buf,
 981                                                           &iwe, buf);
 982                         kfree(buf);
 983                         break;
 984                 case WLAN_EID_SUPP_RATES:
 985                 case WLAN_EID_EXT_SUPP_RATES:
 986                         /* display all supported rates in readable format */
 987                         p = current_ev + iwe_stream_lcp_len(info);
 988
 989                         memset(&iwe, 0, sizeof(iwe));
 990                         iwe.cmd = SIOCGIWRATE;
 991                         /* Those two flags are ignored... */
 992                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 993
 994                         for (i = 0; i < ie[1]; i++) {
 995                                 iwe.u.bitrate.value =
 996                                         ((ie[i + 2] & 0x7f) * 500000);
 997                                 p = iwe_stream_add_value(info, current_ev, p,
 998                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
 999                         }
1000                         current_ev = p;
1001                         break;
1002                 }
1003                 rem -= ie[1] + 2;
1004                 ie += ie[1] + 2;
1005         }
1006
1007         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1008             ismesh) {
1009                 memset(&iwe, 0, sizeof(iwe));
1010                 iwe.cmd = SIOCGIWMODE;
1011                 if (ismesh)
1012                         iwe.u.mode = IW_MODE_MESH;
1013                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1014                         iwe.u.mode = IW_MODE_MASTER;
1015                 else
1016                         iwe.u.mode = IW_MODE_ADHOC;
1017                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1018                                                   &iwe, IW_EV_UINT_LEN);
1019         }
1020
1021         buf = kmalloc(30, GFP_ATOMIC);
1022         if (buf) {
1023                 memset(&iwe, 0, sizeof(iwe));
1024                 iwe.cmd = IWEVCUSTOM;
1025                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1026                 iwe.u.data.length = strlen(buf);
1027                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1028                                                   &iwe, buf);
1029                 memset(&iwe, 0, sizeof(iwe));
1030                 iwe.cmd = IWEVCUSTOM;
1031                 sprintf(buf, " Last beacon: %ums ago",
1032                         elapsed_jiffies_msecs(bss->ts));
1033                 iwe.u.data.length = strlen(buf);
1034                 current_ev = iwe_stream_add_point(info, current_ev,
1035                                                   end_buf, &iwe, buf);
1036                 kfree(buf);
1037         }
1038
1039         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1040
1041         return current_ev;
1042 }
1043
1044
1045 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1046                                   struct iw_request_info *info,
1047                                   char *buf, size_t len)
1048 {
1049         char *current_ev = buf;
1050         char *end_buf = buf + len;
1051         struct cfg80211_internal_bss *bss;
1052
1053         spin_lock_bh(&dev->bss_lock);
1054         cfg80211_bss_expire(dev);
1055
1056         list_for_each_entry(bss, &dev->bss_list, list) {
1057                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1058                         spin_unlock_bh(&dev->bss_lock);
1059                         return -E2BIG;
1060                 }
1061                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1062                                            current_ev, end_buf);
1063         }
1064         spin_unlock_bh(&dev->bss_lock);
1065         return current_ev - buf;
1066 }
1067
1068
1069 int cfg80211_wext_giwscan(struct net_device *dev,
1070                           struct iw_request_info *info,
1071                           struct iw_point *data, char *extra)
1072 {
1073         struct cfg80211_registered_device *rdev;
1074         int res;
1075
1076         if (!netif_running(dev))
1077                 return -ENETDOWN;
1078
1079         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1080
1081         if (IS_ERR(rdev))
1082                 return PTR_ERR(rdev);
1083
1084         if (rdev->scan_req) {
1085                 res = -EAGAIN;
1086                 goto out;
1087         }
1088
1089         res = ieee80211_scan_results(rdev, info, extra, data->length);
1090         data->length = 0;
1091         if (res >= 0) {
1092                 data->length = res;
1093                 res = 0;
1094         }
1095
1096  out:
1097         cfg80211_unlock_rdev(rdev);
1098         return res;
1099 }
1100 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1101 #endif