aboutsummaryrefslogtreecommitdiffstats
path: root/hostapd/ap_list.c
diff options
context:
space:
mode:
authorJouni Malinen <j@w1.fi>2006-06-28 05:15:45 (GMT)
committerJouni Malinen <j@w1.fi>2006-06-28 05:15:45 (GMT)
commit4e98d8ed729e34cbc8bfdbcb47810f80f1fa5be0 (patch)
tree1024dd069dbb313cfcee694c21c5e59f7ad7eb61 /hostapd/ap_list.c
parent4374bca999bd5d9f8b5c4ac37156de272a1fe031 (diff)
downloadhostap-history-4e98d8ed729e34cbc8bfdbcb47810f80f1fa5be0.zip
hostap-history-4e98d8ed729e34cbc8bfdbcb47810f80f1fa5be0.tar.gz
hostap-history-4e98d8ed729e34cbc8bfdbcb47810f80f1fa5be0.tar.bz2
Added code for passive scanning, collecting AP neighbor list and doing
OLBC detection (IEEE 802.11g). (from Devicescape)
Diffstat (limited to 'hostapd/ap_list.c')
-rw-r--r--hostapd/ap_list.c465
1 files changed, 465 insertions, 0 deletions
diff --git a/hostapd/ap_list.c b/hostapd/ap_list.c
new file mode 100644
index 0000000..f5bfcfa
--- /dev/null
+++ b/hostapd/ap_list.c
@@ -0,0 +1,465 @@
+/*
+ * hostapd / AP table
+ * Copyright 2002-2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2003-2004, Instant802 Networks, Inc.
+ * Copyright 2006, Devicescape Software, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <time.h>
+
+#include "hostapd.h"
+#include "ieee802_11.h"
+#include "eloop.h"
+#include "ap_list.h"
+#include "hw_features.h"
+#include "beacon.h"
+
+
+struct ieee80211_frame_info {
+ u32 version;
+ u32 length;
+ u64 mactime;
+ u64 hosttime;
+ u32 phytype;
+ u32 channel;
+ u32 datarate;
+ u32 antenna;
+ u32 priority;
+ u32 ssi_type;
+ u32 ssi_signal;
+ u32 ssi_noise;
+ u32 preamble;
+ u32 encoding;
+
+ /* Note: this structure is otherwise identical to capture format used
+ * in linux-wlan-ng, but this additional field is used to provide meta
+ * data about the frame to hostapd. This was the easiest method for
+ * providing this information, but this might change in the future. */
+ u32 msg_type;
+} __attribute__ ((packed));
+
+
+enum ieee80211_phytype {
+ ieee80211_phytype_fhss_dot11_97 = 1,
+ ieee80211_phytype_dsss_dot11_97 = 2,
+ ieee80211_phytype_irbaseband = 3,
+ ieee80211_phytype_dsss_dot11_b = 4,
+ ieee80211_phytype_pbcc_dot11_b = 5,
+ ieee80211_phytype_ofdm_dot11_g = 6,
+ ieee80211_phytype_pbcc_dot11_g = 7,
+ ieee80211_phytype_ofdm_dot11_a = 8,
+ ieee80211_phytype_dsss_dot11_turbog = 255,
+ ieee80211_phytype_dsss_dot11_turbo = 256,
+};
+
+
+/* AP list is a double linked list with head->prev pointing to the end of the
+ * list and tail->next = NULL. Entries are moved to the head of the list
+ * whenever a beacon has been received from the AP in question. The tail entry
+ * in this link will thus be the least recently used entry. */
+
+
+static void ap_list_new_ap(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ wpa_printf(MSG_DEBUG, "New AP detected: " MACSTR, MAC2STR(ap->addr));
+
+ /* TODO: could send a notification message to an external program that
+ * would then determine whether a rogue AP has been detected */
+}
+
+
+static void ap_list_expired_ap(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ wpa_printf(MSG_DEBUG, "AP info expired: " MACSTR, MAC2STR(ap->addr));
+
+ /* TODO: could send a notification message to an external program */
+}
+
+
+static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ int i;
+
+ if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
+ ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
+ iface->conf->channel != ap->channel)
+ return 0;
+
+ if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
+ return 1;
+
+ for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
+ int rate = (ap->supported_rates[i] & 0x7f) * 5;
+ if (rate == 60 || rate == 90 || rate > 110)
+ return 0;
+ }
+
+ return 1;
+}
+
+
+struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
+{
+ struct ap_info *s;
+
+ s = iface->ap_hash[STA_HASH(ap)];
+ while (s != NULL && memcmp(s->addr, ap, ETH_ALEN) != 0)
+ s = s->hnext;
+ return s;
+}
+
+
+static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ if (iface->ap_list) {
+ ap->prev = iface->ap_list->prev;
+ iface->ap_list->prev = ap;
+ } else
+ ap->prev = ap;
+ ap->next = iface->ap_list;
+ iface->ap_list = ap;
+}
+
+
+static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ if (iface->ap_list == ap)
+ iface->ap_list = ap->next;
+ else
+ ap->prev->next = ap->next;
+
+ if (ap->next)
+ ap->next->prev = ap->prev;
+ else if (iface->ap_list)
+ iface->ap_list->prev = ap->prev;
+}
+
+
+static void ap_ap_iter_list_add(struct hostapd_iface *iface,
+ struct ap_info *ap)
+{
+ if (iface->ap_iter_list) {
+ ap->iter_prev = iface->ap_iter_list->iter_prev;
+ iface->ap_iter_list->iter_prev = ap;
+ } else
+ ap->iter_prev = ap;
+ ap->iter_next = iface->ap_iter_list;
+ iface->ap_iter_list = ap;
+}
+
+
+static void ap_ap_iter_list_del(struct hostapd_iface *iface,
+ struct ap_info *ap)
+{
+ if (iface->ap_iter_list == ap)
+ iface->ap_iter_list = ap->iter_next;
+ else
+ ap->iter_prev->iter_next = ap->iter_next;
+
+ if (ap->iter_next)
+ ap->iter_next->iter_prev = ap->iter_prev;
+ else if (iface->ap_iter_list)
+ iface->ap_iter_list->iter_prev = ap->iter_prev;
+}
+
+
+static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
+ iface->ap_hash[STA_HASH(ap->addr)] = ap;
+}
+
+
+static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ struct ap_info *s;
+
+ s = iface->ap_hash[STA_HASH(ap->addr)];
+ if (s == NULL) return;
+ if (memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
+ iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
+ return;
+ }
+
+ while (s->hnext != NULL &&
+ memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
+ s = s->hnext;
+ if (s->hnext != NULL)
+ s->hnext = s->hnext->hnext;
+ else
+ printf("AP: could not remove AP " MACSTR " from hash table\n",
+ MAC2STR(ap->addr));
+}
+
+
+static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
+{
+ ap_ap_hash_del(iface, ap);
+ ap_ap_list_del(iface, ap);
+ ap_ap_iter_list_del(iface, ap);
+
+ iface->num_ap--;
+ free(ap);
+}
+
+
+static void hostapd_free_aps(struct hostapd_iface *iface)
+{
+ struct ap_info *ap, *prev;
+
+ ap = iface->ap_list;
+
+ while (ap) {
+ prev = ap;
+ ap = ap->next;
+ ap_free_ap(iface, prev);
+ }
+
+ iface->ap_list = NULL;
+}
+
+
+int ap_ap_for_each(struct hostapd_iface *iface,
+ int (*func)(struct ap_info *s, void *data), void *data)
+{
+ struct ap_info *s;
+ int ret = 0;
+
+ s = iface->ap_list;
+
+ while (s) {
+ ret = func(s, data);
+ if (ret)
+ break;
+ s = s->next;
+ }
+
+ return ret;
+}
+
+
+static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
+{
+ struct ap_info *ap;
+
+ ap = wpa_zalloc(sizeof(struct ap_info));
+ if (ap == NULL)
+ return NULL;
+
+ /* initialize AP info data */
+ memcpy(ap->addr, addr, ETH_ALEN);
+ ap_ap_list_add(iface, ap);
+ iface->num_ap++;
+ ap_ap_hash_add(iface, ap);
+ ap_ap_iter_list_add(iface, ap);
+
+ if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
+ wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
+ MACSTR " from AP table", MAC2STR(ap->prev->addr));
+ if (iface->conf->passive_scan_interval > 0)
+ ap_list_expired_ap(iface, ap->prev);
+ ap_free_ap(iface, ap->prev);
+ }
+
+ return ap;
+}
+
+
+void ap_list_process_beacon(struct hostapd_iface *iface,
+ struct ieee80211_mgmt *mgmt,
+ struct ieee802_11_elems *elems,
+ struct hostapd_frame_info *fi)
+{
+ struct ap_info *ap;
+ int new_ap = 0;
+ size_t len;
+
+ if (iface->conf->ap_table_max_size < 1)
+ return;
+
+ ap = ap_get_ap(iface, mgmt->bssid);
+ if (!ap) {
+ ap = ap_ap_add(iface, mgmt->bssid);
+ if (!ap) {
+ printf("Failed to allocate AP information entry\n");
+ return;
+ }
+ new_ap = 1;
+ }
+
+ ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
+ ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
+
+ if (elems->ssid) {
+ len = elems->ssid_len;
+ if (len >= sizeof(ap->ssid))
+ len = sizeof(ap->ssid) - 1;
+ memcpy(ap->ssid, elems->ssid, len);
+ ap->ssid[len] = '\0';
+ ap->ssid_len = len;
+ }
+
+ memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
+ len = 0;
+ if (elems->supp_rates) {
+ len = elems->supp_rates_len;
+ if (len > WLAN_SUPP_RATES_MAX)
+ len = WLAN_SUPP_RATES_MAX;
+ memcpy(ap->supported_rates, elems->supp_rates, len);
+ }
+ if (elems->ext_supp_rates) {
+ int len2;
+ if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
+ len2 = WLAN_SUPP_RATES_MAX - len;
+ else
+ len2 = elems->ext_supp_rates_len;
+ memcpy(ap->supported_rates + len, elems->ext_supp_rates, len2);
+ }
+
+ ap->wpa = elems->wpa_ie != NULL;
+
+ if (elems->erp_info && elems->erp_info_len == 1)
+ ap->erp = elems->erp_info[0];
+ else
+ ap->erp = -1;
+
+ if (elems->ds_params && elems->ds_params_len == 1)
+ ap->channel = elems->ds_params[0];
+ else if (fi)
+ ap->channel = fi->channel;
+
+ ap->num_beacons++;
+ time(&ap->last_beacon);
+ if (fi) {
+ ap->phytype = fi->phytype;
+ ap->ssi_signal = fi->ssi_signal;
+ ap->datarate = fi->datarate;
+ }
+
+ if (new_ap) {
+ if (iface->conf->passive_scan_interval > 0)
+ ap_list_new_ap(iface, ap);
+ } else if (ap != iface->ap_list) {
+ /* move AP entry into the beginning of the list so that the
+ * oldest entry is always in the end of the list */
+ ap_ap_list_del(iface, ap);
+ ap_ap_list_add(iface, ap);
+ }
+
+ if (!iface->olbc &&
+ ap_list_beacon_olbc(iface, ap)) {
+ struct hostapd_data *hapd = iface->bss[0];
+ iface->olbc = 1;
+ HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL,
+ "OLBC AP detected: " MACSTR " - enable "
+ "protection\n", MAC2STR(ap->addr));
+ ieee802_11_set_beacons(hapd->iface);
+ }
+}
+
+
+static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
+{
+ struct hostapd_iface *iface = eloop_ctx;
+ time_t now;
+ struct ap_info *ap;
+
+ eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
+
+ if (!iface->ap_list)
+ return;
+
+ time(&now);
+
+ /* FIX: it looks like jkm-Purina ended up in busy loop in this
+ * function. Apparently, something can still cause a loop in the AP
+ * list.. */
+
+ while (iface->ap_list) {
+ ap = iface->ap_list->prev;
+ if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
+ now)
+ break;
+
+ if (iface->conf->passive_scan_interval > 0)
+ ap_list_expired_ap(iface, ap);
+ ap_free_ap(iface, ap);
+ }
+
+ if (iface->olbc) {
+ int olbc = 0;
+ ap = iface->ap_list;
+ while (ap) {
+ if (ap_list_beacon_olbc(iface, ap)) {
+ olbc = 1;
+ break;
+ }
+ ap = ap->next;
+ }
+ if (!olbc) {
+ struct hostapd_data *hapd = iface->bss[0];
+ HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL,
+ "OLBC not detected anymore\n");
+ iface->olbc = 0;
+ ieee802_11_set_beacons(hapd->iface);
+ }
+ }
+}
+
+
+int ap_list_init(struct hostapd_iface *iface)
+{
+ eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
+ return 0;
+}
+
+
+void ap_list_deinit(struct hostapd_iface *iface)
+{
+ eloop_cancel_timeout(ap_list_timer, iface, NULL);
+ hostapd_free_aps(iface);
+}
+
+
+int ap_list_reconfig(struct hostapd_iface *iface,
+ struct hostapd_config *oldconf)
+{
+ time_t now;
+ struct ap_info *ap;
+
+ if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
+ iface->conf->ap_table_expiration_time ==
+ oldconf->ap_table_expiration_time)
+ return 0;
+
+ time(&now);
+
+ while (iface->ap_list) {
+ ap = iface->ap_list->prev;
+ if (iface->num_ap <= iface->conf->ap_table_max_size &&
+ ap->last_beacon + iface->conf->ap_table_expiration_time >=
+ now)
+ break;
+
+ if (iface->conf->passive_scan_interval > 0)
+ ap_list_expired_ap(iface, iface->ap_list->prev);
+ ap_free_ap(iface, iface->ap_list->prev);
+ }
+
+ return 0;
+}