vcs.maemo.org Git - wpasupplicant/blob - 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 "sta_info.h"
  24 #include "ap_list.h"
  25 #include "hw_features.h"
  26 #include "beacon.h"
  27 #include "driver.h"
  28
  29
  30 struct ieee80211_frame_info {
  31         u32 version;
  32         u32 length;
  33         u64 mactime;
  34         u64 hosttime;
  35         u32 phytype;
  36         u32 channel;
  37         u32 datarate;
  38         u32 antenna;
  39         u32 priority;
  40         u32 ssi_type;
  41         u32 ssi_signal;
  42         u32 ssi_noise;
  43         u32 preamble;
  44         u32 encoding;
  45
  46         /* Note: this structure is otherwise identical to capture format used
  47          * in linux-wlan-ng, but this additional field is used to provide meta
  48          * data about the frame to hostapd. This was the easiest method for
  49          * providing this information, but this might change in the future. */
  50         u32 msg_type;
  51 } __attribute__ ((packed));
  52
  53
  54 enum ieee80211_phytype {
  55         ieee80211_phytype_fhss_dot11_97  = 1,
  56         ieee80211_phytype_dsss_dot11_97  = 2,
  57         ieee80211_phytype_irbaseband     = 3,
  58         ieee80211_phytype_dsss_dot11_b   = 4,
  59         ieee80211_phytype_pbcc_dot11_b   = 5,
  60         ieee80211_phytype_ofdm_dot11_g   = 6,
  61         ieee80211_phytype_pbcc_dot11_g   = 7,
  62         ieee80211_phytype_ofdm_dot11_a   = 8,
  63         ieee80211_phytype_dsss_dot11_turbog = 255,
  64         ieee80211_phytype_dsss_dot11_turbo = 256,
  65 };
  66
  67
  68 /* AP list is a double linked list with head->prev pointing to the end of the
  69  * list and tail->next = NULL. Entries are moved to the head of the list
  70  * whenever a beacon has been received from the AP in question. The tail entry
  71  * in this link will thus be the least recently used entry. */
  72
  73
  74 static void ap_list_new_ap(struct hostapd_iface *iface, struct ap_info *ap)
  75 {
  76         wpa_printf(MSG_DEBUG, "New AP detected: " MACSTR, MAC2STR(ap->addr));
  77
  78         /* TODO: could send a notification message to an external program that
  79          * would then determine whether a rogue AP has been detected */
  80 }
  81
  82
  83 static void ap_list_expired_ap(struct hostapd_iface *iface, struct ap_info *ap)
  84 {
  85         wpa_printf(MSG_DEBUG, "AP info expired: " MACSTR, MAC2STR(ap->addr));
  86
  87         /* TODO: could send a notification message to an external program */
  88 }
  89
  90
  91 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  92 {
  93         int i;
  94
  95         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  96             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  97             iface->conf->channel != ap->channel)
  98                 return 0;
  99
 100         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
 101                 return 1;
 102
 103         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
 104                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
 105                 if (rate == 60 || rate == 90 || rate > 110)
 106                         return 0;
 107         }
 108
 109         return 1;
 110 }
 111
 112
 113 #ifdef CONFIG_IEEE80211N
 114 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
 115                                   struct ap_info *ap)
 116 {
 117         return !ap->ht_support;
 118 }
 119 #endif /* CONFIG_IEEE80211N */
 120
 121
 122 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 123 {
 124         struct ap_info *s;
 125
 126         s = iface->ap_hash[STA_HASH(ap)];
 127         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 128                 s = s->hnext;
 129         return s;
 130 }
 131
 132
 133 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 134 {
 135         if (iface->ap_list) {
 136                 ap->prev = iface->ap_list->prev;
 137                 iface->ap_list->prev = ap;
 138         } else
 139                 ap->prev = ap;
 140         ap->next = iface->ap_list;
 141         iface->ap_list = ap;
 142 }
 143
 144
 145 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 146 {
 147         if (iface->ap_list == ap)
 148                 iface->ap_list = ap->next;
 149         else
 150                 ap->prev->next = ap->next;
 151
 152         if (ap->next)
 153                 ap->next->prev = ap->prev;
 154         else if (iface->ap_list)
 155                 iface->ap_list->prev = ap->prev;
 156 }
 157
 158
 159 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 160                                 struct ap_info *ap)
 161 {
 162         if (iface->ap_iter_list) {
 163                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 164                 iface->ap_iter_list->iter_prev = ap;
 165         } else
 166                 ap->iter_prev = ap;
 167         ap->iter_next = iface->ap_iter_list;
 168         iface->ap_iter_list = ap;
 169 }
 170
 171
 172 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 173                                 struct ap_info *ap)
 174 {
 175         if (iface->ap_iter_list == ap)
 176                 iface->ap_iter_list = ap->iter_next;
 177         else
 178                 ap->iter_prev->iter_next = ap->iter_next;
 179
 180         if (ap->iter_next)
 181                 ap->iter_next->iter_prev = ap->iter_prev;
 182         else if (iface->ap_iter_list)
 183                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 184 }
 185
 186
 187 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 188 {
 189         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 190         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 191 }
 192
 193
 194 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 195 {
 196         struct ap_info *s;
 197
 198         s = iface->ap_hash[STA_HASH(ap->addr)];
 199         if (s == NULL) return;
 200         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 201                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 202                 return;
 203         }
 204
 205         while (s->hnext != NULL &&
 206                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 207                 s = s->hnext;
 208         if (s->hnext != NULL)
 209                 s->hnext = s->hnext->hnext;
 210         else
 211                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 212                        MAC2STR(ap->addr));
 213 }
 214
 215
 216 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 217 {
 218         ap_ap_hash_del(iface, ap);
 219         ap_ap_list_del(iface, ap);
 220         ap_ap_iter_list_del(iface, ap);
 221
 222         iface->num_ap--;
 223         os_free(ap);
 224 }
 225
 226
 227 static void hostapd_free_aps(struct hostapd_iface *iface)
 228 {
 229         struct ap_info *ap, *prev;
 230
 231         ap = iface->ap_list;
 232
 233         while (ap) {
 234                 prev = ap;
 235                 ap = ap->next;
 236                 ap_free_ap(iface, prev);
 237         }
 238
 239         iface->ap_list = NULL;
 240 }
 241
 242
 243 int ap_ap_for_each(struct hostapd_iface *iface,
 244                    int (*func)(struct ap_info *s, void *data), void *data)
 245 {
 246         struct ap_info *s;
 247         int ret = 0;
 248
 249         s = iface->ap_list;
 250
 251         while (s) {
 252                 ret = func(s, data);
 253                 if (ret)
 254                         break;
 255                 s = s->next;
 256         }
 257
 258         return ret;
 259 }
 260
 261
 262 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 263 {
 264         struct ap_info *ap;
 265
 266         ap = os_zalloc(sizeof(struct ap_info));
 267         if (ap == NULL)
 268                 return NULL;
 269
 270         /* initialize AP info data */
 271         os_memcpy(ap->addr, addr, ETH_ALEN);
 272         ap_ap_list_add(iface, ap);
 273         iface->num_ap++;
 274         ap_ap_hash_add(iface, ap);
 275         ap_ap_iter_list_add(iface, ap);
 276
 277         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 278                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 279                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 280                 if (iface->conf->passive_scan_interval > 0)
 281                         ap_list_expired_ap(iface, ap->prev);
 282                 ap_free_ap(iface, ap->prev);
 283         }
 284
 285         return ap;
 286 }
 287
 288
 289 void ap_list_process_beacon(struct hostapd_iface *iface,
 290                             struct ieee80211_mgmt *mgmt,
 291                             struct ieee802_11_elems *elems,
 292                             struct hostapd_frame_info *fi)
 293 {
 294         struct ap_info *ap;
 295         int new_ap = 0;
 296         size_t len;
 297         int set_beacon = 0;
 298
 299         if (iface->conf->ap_table_max_size < 1)
 300                 return;
 301
 302         ap = ap_get_ap(iface, mgmt->bssid);
 303         if (!ap) {
 304                 ap = ap_ap_add(iface, mgmt->bssid);
 305                 if (!ap) {
 306                         printf("Failed to allocate AP information entry\n");
 307                         return;
 308                 }
 309                 new_ap = 1;
 310         }
 311
 312         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 313         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 314
 315         if (elems->ssid) {
 316                 len = elems->ssid_len;
 317                 if (len >= sizeof(ap->ssid))
 318                         len = sizeof(ap->ssid) - 1;
 319                 os_memcpy(ap->ssid, elems->ssid, len);
 320                 ap->ssid[len] = '\0';
 321                 ap->ssid_len = len;
 322         }
 323
 324         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 325         len = 0;
 326         if (elems->supp_rates) {
 327                 len = elems->supp_rates_len;
 328                 if (len > WLAN_SUPP_RATES_MAX)
 329                         len = WLAN_SUPP_RATES_MAX;
 330                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 331         }
 332         if (elems->ext_supp_rates) {
 333                 int len2;
 334                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 335                         len2 = WLAN_SUPP_RATES_MAX - len;
 336                 else
 337                         len2 = elems->ext_supp_rates_len;
 338                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 339                           len2);
 340         }
 341
 342         ap->wpa = elems->wpa_ie != NULL;
 343
 344         if (elems->erp_info && elems->erp_info_len == 1)
 345                 ap->erp = elems->erp_info[0];
 346         else
 347                 ap->erp = -1;
 348
 349         if (elems->ds_params && elems->ds_params_len == 1)
 350                 ap->channel = elems->ds_params[0];
 351         else if (fi)
 352                 ap->channel = fi->channel;
 353
 354         if (elems->ht_capabilities)
 355                 ap->ht_support = 1;
 356         else
 357                 ap->ht_support = 0;
 358
 359         ap->num_beacons++;
 360         time(&ap->last_beacon);
 361         if (fi) {
 362                 ap->phytype = fi->phytype;
 363                 ap->ssi_signal = fi->ssi_signal;
 364                 ap->datarate = fi->datarate;
 365         }
 366
 367         if (new_ap) {
 368                 if (iface->conf->passive_scan_interval > 0)
 369                         ap_list_new_ap(iface, ap);
 370         } else if (ap != iface->ap_list) {
 371                 /* move AP entry into the beginning of the list so that the
 372                  * oldest entry is always in the end of the list */
 373                 ap_ap_list_del(iface, ap);
 374                 ap_ap_list_add(iface, ap);
 375         }
 376
 377         if (!iface->olbc &&
 378             ap_list_beacon_olbc(iface, ap)) {
 379                 iface->olbc = 1;
 380                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 381                            "protection", MAC2STR(ap->addr));
 382                 set_beacon++;
 383         }
 384
 385 #ifdef CONFIG_IEEE80211N
 386         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 387                 iface->olbc_ht = 1;
 388                 hostapd_ht_operation_update(iface);
 389                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 390                            " - enable protection", MAC2STR(ap->addr));
 391                 set_beacon++;
 392         }
 393 #endif /* CONFIG_IEEE80211N */
 394
 395         if (set_beacon)
 396                 ieee802_11_set_beacons(iface);
 397 }
 398
 399
 400 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 401 {
 402         struct hostapd_iface *iface = eloop_ctx;
 403         time_t now;
 404         struct ap_info *ap;
 405         int set_beacon = 0;
 406
 407         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 408
 409         if (!iface->ap_list)
 410                 return;
 411
 412         time(&now);
 413
 414         /* FIX: it looks like jkm-Purina ended up in busy loop in this
 415          * function. Apparently, something can still cause a loop in the AP
 416          * list.. */
 417
 418         while (iface->ap_list) {
 419                 ap = iface->ap_list->prev;
 420                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 421                     now)
 422                         break;
 423
 424                 if (iface->conf->passive_scan_interval > 0)
 425                         ap_list_expired_ap(iface, ap);
 426                 ap_free_ap(iface, ap);
 427         }
 428
 429         if (iface->olbc || iface->olbc_ht) {
 430                 int olbc = 0;
 431                 int olbc_ht = 0;
 432
 433                 ap = iface->ap_list;
 434                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 435                         if (ap_list_beacon_olbc(iface, ap))
 436                                 olbc = 1;
 437 #ifdef CONFIG_IEEE80211N
 438                         if (ap_list_beacon_olbc_ht(iface, ap))
 439                                 olbc_ht = 1;
 440 #endif /* CONFIG_IEEE80211N */
 441                         ap = ap->next;
 442                 }
 443                 if (!olbc && iface->olbc) {
 444                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 445                         iface->olbc = 0;
 446                         set_beacon++;
 447                 }
 448 #ifdef CONFIG_IEEE80211N
 449                 if (!olbc_ht && iface->olbc_ht) {
 450                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 451                         iface->olbc_ht = 0;
 452                         hostapd_ht_operation_update(iface);
 453                         set_beacon++;
 454                 }
 455 #endif /* CONFIG_IEEE80211N */
 456         }
 457
 458         if (set_beacon)
 459                 ieee802_11_set_beacons(iface);
 460 }
 461
 462
 463 int ap_list_init(struct hostapd_iface *iface)
 464 {
 465         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 466         return 0;
 467 }
 468
 469
 470 void ap_list_deinit(struct hostapd_iface *iface)
 471 {
 472         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 473         hostapd_free_aps(iface);
 474 }
 475
 476
 477 int ap_list_reconfig(struct hostapd_iface *iface,
 478                      struct hostapd_config *oldconf)
 479 {
 480         time_t now;
 481         struct ap_info *ap;
 482
 483         if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
 484             iface->conf->ap_table_expiration_time ==
 485             oldconf->ap_table_expiration_time)
 486                 return 0;
 487
 488         time(&now);
 489
 490         while (iface->ap_list) {
 491                 ap = iface->ap_list->prev;
 492                 if (iface->num_ap <= iface->conf->ap_table_max_size &&
 493                     ap->last_beacon + iface->conf->ap_table_expiration_time >=
 494                     now)
 495                         break;
 496
 497                 if (iface->conf->passive_scan_interval > 0)
 498                         ap_list_expired_ap(iface, iface->ap_list->prev);
 499                 ap_free_ap(iface, iface->ap_list->prev);
 500         }
 501
 502         return 0;
 503 }