contrib/hostapd/hostapd/ap_list.c

   1 /*
   2  * hostapd / AP table
   3  * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
   4  * Copyright (c) 2003-2004, Instant802 Networks, Inc.
   5  * Copyright (c) 2006, Devicescape Software, Inc.
   6  * Copyright (c) 2007-2008, Intel Corporation
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Alternatively, this software may be distributed under the terms of BSD
  13  * license.
  14  *
  15  * See README and COPYING for more details.
  16  */
  17
  18 #include "includes.h"
  19
  20 #include "hostapd.h"
  21 #include "ieee802_11.h"
  22 #include "eloop.h"
  23 #include "ap_list.h"
  24 #include "hw_features.h"
  25 #include "beacon.h"
  26
  27
  28 struct ieee80211_frame_info {
  29         u32 version;
  30         u32 length;
  31         u64 mactime;
  32         u64 hosttime;
  33         u32 phytype;
  34         u32 channel;
  35         u32 datarate;
  36         u32 antenna;
  37         u32 priority;
  38         u32 ssi_type;
  39         u32 ssi_signal;
  40         u32 ssi_noise;
  41         u32 preamble;
  42         u32 encoding;
  43
  44         /* Note: this structure is otherwise identical to capture format used
  45          * in linux-wlan-ng, but this additional field is used to provide meta
  46          * data about the frame to hostapd. This was the easiest method for
  47          * providing this information, but this might change in the future. */
  48         u32 msg_type;
  49 } __attribute__ ((packed));
  50
  51
  52 enum ieee80211_phytype {
  53         ieee80211_phytype_fhss_dot11_97  = 1,
  54         ieee80211_phytype_dsss_dot11_97  = 2,
  55         ieee80211_phytype_irbaseband     = 3,
  56         ieee80211_phytype_dsss_dot11_b   = 4,
  57         ieee80211_phytype_pbcc_dot11_b   = 5,
  58         ieee80211_phytype_ofdm_dot11_g   = 6,
  59         ieee80211_phytype_pbcc_dot11_g   = 7,
  60         ieee80211_phytype_ofdm_dot11_a   = 8,
  61         ieee80211_phytype_dsss_dot11_turbog = 255,
  62         ieee80211_phytype_dsss_dot11_turbo = 256,
  63 };
  64
  65
  66 /* AP list is a double linked list with head->prev pointing to the end of the
  67  * list and tail->next = NULL. Entries are moved to the head of the list
  68  * whenever a beacon has been received from the AP in question. The tail entry
  69  * in this link will thus be the least recently used entry. */
  70
  71
  72 static void ap_list_new_ap(struct hostapd_iface *iface, struct ap_info *ap)
  73 {
  74         wpa_printf(MSG_DEBUG, "New AP detected: " MACSTR, MAC2STR(ap->addr));
  75
  76         /* TODO: could send a notification message to an external program that
  77          * would then determine whether a rogue AP has been detected */
  78 }
  79
  80
  81 static void ap_list_expired_ap(struct hostapd_iface *iface, struct ap_info *ap)
  82 {
  83         wpa_printf(MSG_DEBUG, "AP info expired: " MACSTR, MAC2STR(ap->addr));
  84
  85         /* TODO: could send a notification message to an external program */
  86 }
  87
  88
  89 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  90 {
  91         int i;
  92
  93         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  94             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  95             iface->conf->channel != ap->channel)
  96                 return 0;
  97
  98         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
  99                 return 1;
 100
 101         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
 102                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
 103                 if (rate == 60 || rate == 90 || rate > 110)
 104                         return 0;
 105         }
 106
 107         return 1;
 108 }
 109
 110
 111 #ifdef CONFIG_IEEE80211N
 112 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
 113                                   struct ap_info *ap)
 114 {
 115         return !ap->ht_support;
 116 }
 117 #endif /* CONFIG_IEEE80211N */
 118
 119
 120 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 121 {
 122         struct ap_info *s;
 123
 124         s = iface->ap_hash[STA_HASH(ap)];
 125         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 126                 s = s->hnext;
 127         return s;
 128 }
 129
 130
 131 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 132 {
 133         if (iface->ap_list) {
 134                 ap->prev = iface->ap_list->prev;
 135                 iface->ap_list->prev = ap;
 136         } else
 137                 ap->prev = ap;
 138         ap->next = iface->ap_list;
 139         iface->ap_list = ap;
 140 }
 141
 142
 143 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 144 {
 145         if (iface->ap_list == ap)
 146                 iface->ap_list = ap->next;
 147         else
 148                 ap->prev->next = ap->next;
 149
 150         if (ap->next)
 151                 ap->next->prev = ap->prev;
 152         else if (iface->ap_list)
 153                 iface->ap_list->prev = ap->prev;
 154 }
 155
 156
 157 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 158                                 struct ap_info *ap)
 159 {
 160         if (iface->ap_iter_list) {
 161                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 162                 iface->ap_iter_list->iter_prev = ap;
 163         } else
 164                 ap->iter_prev = ap;
 165         ap->iter_next = iface->ap_iter_list;
 166         iface->ap_iter_list = ap;
 167 }
 168
 169
 170 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 171                                 struct ap_info *ap)
 172 {
 173         if (iface->ap_iter_list == ap)
 174                 iface->ap_iter_list = ap->iter_next;
 175         else
 176                 ap->iter_prev->iter_next = ap->iter_next;
 177
 178         if (ap->iter_next)
 179                 ap->iter_next->iter_prev = ap->iter_prev;
 180         else if (iface->ap_iter_list)
 181                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 182 }
 183
 184
 185 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 186 {
 187         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 188         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 189 }
 190
 191
 192 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 193 {
 194         struct ap_info *s;
 195
 196         s = iface->ap_hash[STA_HASH(ap->addr)];
 197         if (s == NULL) return;
 198         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 199                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 200                 return;
 201         }
 202
 203         while (s->hnext != NULL &&
 204                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 205                 s = s->hnext;
 206         if (s->hnext != NULL)
 207                 s->hnext = s->hnext->hnext;
 208         else
 209                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 210                        MAC2STR(ap->addr));
 211 }
 212
 213
 214 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 215 {
 216         ap_ap_hash_del(iface, ap);
 217         ap_ap_list_del(iface, ap);
 218         ap_ap_iter_list_del(iface, ap);
 219
 220         iface->num_ap--;
 221         os_free(ap);
 222 }
 223
 224
 225 static void hostapd_free_aps(struct hostapd_iface *iface)
 226 {
 227         struct ap_info *ap, *prev;
 228
 229         ap = iface->ap_list;
 230
 231         while (ap) {
 232                 prev = ap;
 233                 ap = ap->next;
 234                 ap_free_ap(iface, prev);
 235         }
 236
 237         iface->ap_list = NULL;
 238 }
 239
 240
 241 int ap_ap_for_each(struct hostapd_iface *iface,
 242                    int (*func)(struct ap_info *s, void *data), void *data)
 243 {
 244         struct ap_info *s;
 245         int ret = 0;
 246
 247         s = iface->ap_list;
 248
 249         while (s) {
 250                 ret = func(s, data);
 251                 if (ret)
 252                         break;
 253                 s = s->next;
 254         }
 255
 256         return ret;
 257 }
 258
 259
 260 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 261 {
 262         struct ap_info *ap;
 263
 264         ap = os_zalloc(sizeof(struct ap_info));
 265         if (ap == NULL)
 266                 return NULL;
 267
 268         /* initialize AP info data */
 269         os_memcpy(ap->addr, addr, ETH_ALEN);
 270         ap_ap_list_add(iface, ap);
 271         iface->num_ap++;
 272         ap_ap_hash_add(iface, ap);
 273         ap_ap_iter_list_add(iface, ap);
 274
 275         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 276                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 277                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 278                 if (iface->conf->passive_scan_interval > 0)
 279                         ap_list_expired_ap(iface, ap->prev);
 280                 ap_free_ap(iface, ap->prev);
 281         }
 282
 283         return ap;
 284 }
 285
 286
 287 void ap_list_process_beacon(struct hostapd_iface *iface,
 288                             struct ieee80211_mgmt *mgmt,
 289                             struct ieee802_11_elems *elems,
 290                             struct hostapd_frame_info *fi)
 291 {
 292         struct ap_info *ap;
 293         int new_ap = 0;
 294         size_t len;
 295         int set_beacon = 0;
 296
 297         if (iface->conf->ap_table_max_size < 1)
 298                 return;
 299
 300         ap = ap_get_ap(iface, mgmt->bssid);
 301         if (!ap) {
 302                 ap = ap_ap_add(iface, mgmt->bssid);
 303                 if (!ap) {
 304                         printf("Failed to allocate AP information entry\n");
 305                         return;
 306                 }
 307                 new_ap = 1;
 308         }
 309
 310         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 311         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 312
 313         if (elems->ssid) {
 314                 len = elems->ssid_len;
 315                 if (len >= sizeof(ap->ssid))
 316                         len = sizeof(ap->ssid) - 1;
 317                 os_memcpy(ap->ssid, elems->ssid, len);
 318                 ap->ssid[len] = '\0';
 319                 ap->ssid_len = len;
 320         }
 321
 322         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 323         len = 0;
 324         if (elems->supp_rates) {
 325                 len = elems->supp_rates_len;
 326                 if (len > WLAN_SUPP_RATES_MAX)
 327                         len = WLAN_SUPP_RATES_MAX;
 328                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 329         }
 330         if (elems->ext_supp_rates) {
 331                 int len2;
 332                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 333                         len2 = WLAN_SUPP_RATES_MAX - len;
 334                 else
 335                         len2 = elems->ext_supp_rates_len;
 336                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 337                           len2);
 338         }
 339
 340         ap->wpa = elems->wpa_ie != NULL;
 341
 342         if (elems->erp_info && elems->erp_info_len == 1)
 343                 ap->erp = elems->erp_info[0];
 344         else
 345                 ap->erp = -1;
 346
 347         if (elems->ds_params && elems->ds_params_len == 1)
 348                 ap->channel = elems->ds_params[0];
 349         else if (fi)
 350                 ap->channel = fi->channel;
 351
 352         if (elems->ht_capabilities)
 353                 ap->ht_support = 1;
 354         else
 355                 ap->ht_support = 0;
 356
 357         ap->num_beacons++;
 358         time(&ap->last_beacon);
 359         if (fi) {
 360                 ap->phytype = fi->phytype;
 361                 ap->ssi_signal = fi->ssi_signal;
 362                 ap->datarate = fi->datarate;
 363         }
 364
 365         if (new_ap) {
 366                 if (iface->conf->passive_scan_interval > 0)
 367                         ap_list_new_ap(iface, ap);
 368         } else if (ap != iface->ap_list) {
 369                 /* move AP entry into the beginning of the list so that the
 370                  * oldest entry is always in the end of the list */
 371                 ap_ap_list_del(iface, ap);
 372                 ap_ap_list_add(iface, ap);
 373         }
 374
 375         if (!iface->olbc &&
 376             ap_list_beacon_olbc(iface, ap)) {
 377                 iface->olbc = 1;
 378                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 379                            "protection", MAC2STR(ap->addr));
 380                 set_beacon++;
 381         }
 382
 383 #ifdef CONFIG_IEEE80211N
 384         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 385                 iface->olbc_ht = 1;
 386                 hostapd_ht_operation_update(iface);
 387                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 388                            " - enable protection", MAC2STR(ap->addr));
 389                 set_beacon++;
 390         }
 391 #endif /* CONFIG_IEEE80211N */
 392
 393         if (set_beacon)
 394                 ieee802_11_set_beacons(iface);
 395 }
 396
 397
 398 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 399 {
 400         struct hostapd_iface *iface = eloop_ctx;
 401         time_t now;
 402         struct ap_info *ap;
 403         int set_beacon = 0;
 404
 405         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 406
 407         if (!iface->ap_list)
 408                 return;
 409
 410         time(&now);
 411
 412         /* FIX: it looks like jkm-Purina ended up in busy loop in this
 413          * function. Apparently, something can still cause a loop in the AP
 414          * list.. */
 415
 416         while (iface->ap_list) {
 417                 ap = iface->ap_list->prev;
 418                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 419                     now)
 420                         break;
 421
 422                 if (iface->conf->passive_scan_interval > 0)
 423                         ap_list_expired_ap(iface, ap);
 424                 ap_free_ap(iface, ap);
 425         }
 426
 427         if (iface->olbc || iface->olbc_ht) {
 428                 int olbc = 0;
 429                 int olbc_ht = 0;
 430
 431                 ap = iface->ap_list;
 432                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 433                         if (ap_list_beacon_olbc(iface, ap))
 434                                 olbc = 1;
 435 #ifdef CONFIG_IEEE80211N
 436                         if (ap_list_beacon_olbc_ht(iface, ap))
 437                                 olbc_ht = 1;
 438 #endif /* CONFIG_IEEE80211N */
 439                         ap = ap->next;
 440                 }
 441                 if (!olbc && iface->olbc) {
 442                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 443                         iface->olbc = 0;
 444                         set_beacon++;
 445                 }
 446 #ifdef CONFIG_IEEE80211N
 447                 if (!olbc_ht && iface->olbc_ht) {
 448                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 449                         iface->olbc_ht = 0;
 450                         hostapd_ht_operation_update(iface);
 451                         set_beacon++;
 452                 }
 453 #endif /* CONFIG_IEEE80211N */
 454         }
 455
 456         if (set_beacon)
 457                 ieee802_11_set_beacons(iface);
 458 }
 459
 460
 461 int ap_list_init(struct hostapd_iface *iface)
 462 {
 463         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 464         return 0;
 465 }
 466
 467
 468 void ap_list_deinit(struct hostapd_iface *iface)
 469 {
 470         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 471         hostapd_free_aps(iface);
 472 }
 473
 474
 475 int ap_list_reconfig(struct hostapd_iface *iface,
 476                      struct hostapd_config *oldconf)
 477 {
 478         time_t now;
 479         struct ap_info *ap;
 480
 481         if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
 482             iface->conf->ap_table_expiration_time ==
 483             oldconf->ap_table_expiration_time)
 484                 return 0;
 485
 486         time(&now);
 487
 488         while (iface->ap_list) {
 489                 ap = iface->ap_list->prev;
 490                 if (iface->num_ap <= iface->conf->ap_table_max_size &&
 491                     ap->last_beacon + iface->conf->ap_table_expiration_time >=
 492                     now)
 493                         break;
 494
 495                 if (iface->conf->passive_scan_interval > 0)
 496                         ap_list_expired_ap(iface, iface->ap_list->prev);
 497                 ap_free_ap(iface, iface->ap_list->prev);
 498         }
 499
 500         return 0;
 501 }