wpa_supplicant_node: wpa_supplicant_node: ap

00001 /*
00002  * hostapd / AP table
00003  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
00004  * Copyright (c) 2003-2004, Instant802 Networks, Inc.
00005  * Copyright (c) 2006, Devicescape Software, Inc.
00006  *
00007  * This program is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License version 2 as
00009  * published by the Free Software Foundation.
00010  *
00011  * Alternatively, this software may be distributed under the terms of BSD
00012  * license.
00013  *
00014  * See README and COPYING for more details.
00015  */
00016 
00017 #include "utils/includes.h"
00018 
00019 #include "utils/common.h"
00020 #include "utils/eloop.h"
00021 #include "common/ieee802_11_defs.h"
00022 #include "common/ieee802_11_common.h"
00023 #include "drivers/driver.h"
00024 #include "hostapd.h"
00025 #include "ap_config.h"
00026 #include "ieee802_11.h"
00027 #include "sta_info.h"
00028 #include "beacon.h"
00029 #include "ap_list.h"
00030 
00031 
00032 /* AP list is a double linked list with head->prev pointing to the end of the
00033  * list and tail->next = NULL. Entries are moved to the head of the list
00034  * whenever a beacon has been received from the AP in question. The tail entry
00035  * in this link will thus be the least recently used entry. */
00036 
00037 
00038 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
00039 {
00040         int i;
00041 
00042         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
00043             iface->conf->channel != ap->channel)
00044                 return 0;
00045 
00046         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
00047                 return 1;
00048 
00049         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
00050                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
00051                 if (rate == 60 || rate == 90 || rate > 110)
00052                         return 0;
00053         }
00054 
00055         return 1;
00056 }
00057 
00058 
00059 struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
00060 {
00061         struct ap_info *s;
00062 
00063         s = iface->ap_hash[STA_HASH(ap)];
00064         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
00065                 s = s->hnext;
00066         return s;
00067 }
00068 
00069 
00070 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
00071 {
00072         if (iface->ap_list) {
00073                 ap->prev = iface->ap_list->prev;
00074                 iface->ap_list->prev = ap;
00075         } else
00076                 ap->prev = ap;
00077         ap->next = iface->ap_list;
00078         iface->ap_list = ap;
00079 }
00080 
00081 
00082 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
00083 {
00084         if (iface->ap_list == ap)
00085                 iface->ap_list = ap->next;
00086         else
00087                 ap->prev->next = ap->next;
00088 
00089         if (ap->next)
00090                 ap->next->prev = ap->prev;
00091         else if (iface->ap_list)
00092                 iface->ap_list->prev = ap->prev;
00093 }
00094 
00095 
00096 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
00097                                 struct ap_info *ap)
00098 {
00099         if (iface->ap_iter_list) {
00100                 ap->iter_prev = iface->ap_iter_list->iter_prev;
00101                 iface->ap_iter_list->iter_prev = ap;
00102         } else
00103                 ap->iter_prev = ap;
00104         ap->iter_next = iface->ap_iter_list;
00105         iface->ap_iter_list = ap;
00106 }
00107 
00108 
00109 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
00110                                 struct ap_info *ap)
00111 {
00112         if (iface->ap_iter_list == ap)
00113                 iface->ap_iter_list = ap->iter_next;
00114         else
00115                 ap->iter_prev->iter_next = ap->iter_next;
00116 
00117         if (ap->iter_next)
00118                 ap->iter_next->iter_prev = ap->iter_prev;
00119         else if (iface->ap_iter_list)
00120                 iface->ap_iter_list->iter_prev = ap->iter_prev;
00121 }
00122 
00123 
00124 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
00125 {
00126         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
00127         iface->ap_hash[STA_HASH(ap->addr)] = ap;
00128 }
00129 
00130 
00131 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
00132 {
00133         struct ap_info *s;
00134 
00135         s = iface->ap_hash[STA_HASH(ap->addr)];
00136         if (s == NULL) return;
00137         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
00138                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
00139                 return;
00140         }
00141 
00142         while (s->hnext != NULL &&
00143                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
00144                 s = s->hnext;
00145         if (s->hnext != NULL)
00146                 s->hnext = s->hnext->hnext;
00147         else
00148                 printf("AP: could not remove AP " MACSTR " from hash table\n",
00149                        MAC2STR(ap->addr));
00150 }
00151 
00152 
00153 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
00154 {
00155         ap_ap_hash_del(iface, ap);
00156         ap_ap_list_del(iface, ap);
00157         ap_ap_iter_list_del(iface, ap);
00158 
00159         iface->num_ap--;
00160         os_free(ap);
00161 }
00162 
00163 
00164 static void hostapd_free_aps(struct hostapd_iface *iface)
00165 {
00166         struct ap_info *ap, *prev;
00167 
00168         ap = iface->ap_list;
00169 
00170         while (ap) {
00171                 prev = ap;
00172                 ap = ap->next;
00173                 ap_free_ap(iface, prev);
00174         }
00175 
00176         iface->ap_list = NULL;
00177 }
00178 
00179 
00180 int ap_ap_for_each(struct hostapd_iface *iface,
00181                    int (*func)(struct ap_info *s, void *data), void *data)
00182 {
00183         struct ap_info *s;
00184         int ret = 0;
00185 
00186         s = iface->ap_list;
00187 
00188         while (s) {
00189                 ret = func(s, data);
00190                 if (ret)
00191                         break;
00192                 s = s->next;
00193         }
00194 
00195         return ret;
00196 }
00197 
00198 
00199 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
00200 {
00201         struct ap_info *ap;
00202 
00203         ap = os_zalloc(sizeof(struct ap_info));
00204         if (ap == NULL)
00205                 return NULL;
00206 
00207         /* initialize AP info data */
00208         os_memcpy(ap->addr, addr, ETH_ALEN);
00209         ap_ap_list_add(iface, ap);
00210         iface->num_ap++;
00211         ap_ap_hash_add(iface, ap);
00212         ap_ap_iter_list_add(iface, ap);
00213 
00214         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
00215                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
00216                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
00217                 ap_free_ap(iface, ap->prev);
00218         }
00219 
00220         return ap;
00221 }
00222 
00223 
00224 void ap_list_process_beacon(struct hostapd_iface *iface,
00225                             const struct ieee80211_mgmt *mgmt,
00226                             struct ieee802_11_elems *elems,
00227                             struct hostapd_frame_info *fi)
00228 {
00229         struct ap_info *ap;
00230         int new_ap = 0;
00231         size_t len;
00232         int set_beacon = 0;
00233 
00234         if (iface->conf->ap_table_max_size < 1)
00235                 return;
00236 
00237         ap = ap_get_ap(iface, mgmt->bssid);
00238         if (!ap) {
00239                 ap = ap_ap_add(iface, mgmt->bssid);
00240                 if (!ap) {
00241                         printf("Failed to allocate AP information entry\n");
00242                         return;
00243                 }
00244                 new_ap = 1;
00245         }
00246 
00247         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
00248         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
00249 
00250         if (elems->ssid) {
00251                 len = elems->ssid_len;
00252                 if (len >= sizeof(ap->ssid))
00253                         len = sizeof(ap->ssid) - 1;
00254                 os_memcpy(ap->ssid, elems->ssid, len);
00255                 ap->ssid[len] = '\0';
00256                 ap->ssid_len = len;
00257         }
00258 
00259         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
00260         len = 0;
00261         if (elems->supp_rates) {
00262                 len = elems->supp_rates_len;
00263                 if (len > WLAN_SUPP_RATES_MAX)
00264                         len = WLAN_SUPP_RATES_MAX;
00265                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
00266         }
00267         if (elems->ext_supp_rates) {
00268                 int len2;
00269                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
00270                         len2 = WLAN_SUPP_RATES_MAX - len;
00271                 else
00272                         len2 = elems->ext_supp_rates_len;
00273                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
00274                           len2);
00275         }
00276 
00277         ap->wpa = elems->wpa_ie != NULL;
00278 
00279         if (elems->erp_info && elems->erp_info_len == 1)
00280                 ap->erp = elems->erp_info[0];
00281         else
00282                 ap->erp = -1;
00283 
00284         if (elems->ds_params && elems->ds_params_len == 1)
00285                 ap->channel = elems->ds_params[0];
00286         else if (fi)
00287                 ap->channel = fi->channel;
00288 
00289         if (elems->ht_capabilities)
00290                 ap->ht_support = 1;
00291         else
00292                 ap->ht_support = 0;
00293 
00294         ap->num_beacons++;
00295         time(&ap->last_beacon);
00296         if (fi) {
00297                 ap->ssi_signal = fi->ssi_signal;
00298                 ap->datarate = fi->datarate;
00299         }
00300 
00301         if (!new_ap && ap != iface->ap_list) {
00302                 /* move AP entry into the beginning of the list so that the
00303                  * oldest entry is always in the end of the list */
00304                 ap_ap_list_del(iface, ap);
00305                 ap_ap_list_add(iface, ap);
00306         }
00307 
00308         if (!iface->olbc &&
00309             ap_list_beacon_olbc(iface, ap)) {
00310                 iface->olbc = 1;
00311                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
00312                            "protection", MAC2STR(ap->addr));
00313                 set_beacon++;
00314         }
00315 
00316 #ifdef CONFIG_IEEE80211N
00317         if (!iface->olbc_ht && !ap->ht_support) {
00318                 iface->olbc_ht = 1;
00319                 hostapd_ht_operation_update(iface);
00320                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
00321                            " - enable protection", MAC2STR(ap->addr));
00322                 set_beacon++;
00323         }
00324 #endif /* CONFIG_IEEE80211N */
00325 
00326         if (set_beacon)
00327                 ieee802_11_set_beacons(iface);
00328 }
00329 
00330 
00331 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
00332 {
00333         struct hostapd_iface *iface = eloop_ctx;
00334         time_t now;
00335         struct ap_info *ap;
00336         int set_beacon = 0;
00337 
00338         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
00339 
00340         if (!iface->ap_list)
00341                 return;
00342 
00343         time(&now);
00344 
00345         while (iface->ap_list) {
00346                 ap = iface->ap_list->prev;
00347                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
00348                     now)
00349                         break;
00350 
00351                 ap_free_ap(iface, ap);
00352         }
00353 
00354         if (iface->olbc || iface->olbc_ht) {
00355                 int olbc = 0;
00356                 int olbc_ht = 0;
00357 
00358                 ap = iface->ap_list;
00359                 while (ap && (olbc == 0 || olbc_ht == 0)) {
00360                         if (ap_list_beacon_olbc(iface, ap))
00361                                 olbc = 1;
00362                         if (!ap->ht_support)
00363                                 olbc_ht = 1;
00364                         ap = ap->next;
00365                 }
00366                 if (!olbc && iface->olbc) {
00367                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
00368                         iface->olbc = 0;
00369                         set_beacon++;
00370                 }
00371 #ifdef CONFIG_IEEE80211N
00372                 if (!olbc_ht && iface->olbc_ht) {
00373                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
00374                         iface->olbc_ht = 0;
00375                         hostapd_ht_operation_update(iface);
00376                         set_beacon++;
00377                 }
00378 #endif /* CONFIG_IEEE80211N */
00379         }
00380 
00381         if (set_beacon)
00382                 ieee802_11_set_beacons(iface);
00383 }
00384 
00385 
00386 int ap_list_init(struct hostapd_iface *iface)
00387 {
00388         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
00389         return 0;
00390 }
00391 
00392 
00393 void ap_list_deinit(struct hostapd_iface *iface)
00394 {
00395         eloop_cancel_timeout(ap_list_timer, iface, NULL);
00396         hostapd_free_aps(iface);
00397 }
ap_list.c
