wpa_supplicant: Initial Revision 0.8.X
Based on:
commit 0725cc7b7efc434910e89865c42eda7ce61bbf08
Author: Jouni Malinen <j@w1.fi>
Date: Thu Apr 21 20:41:01 2011 +0300
Enable CONFIG_DRIVER_NL80211=y in the default configuration
nl80211 should be preferred over WEXT with any recent Linux
kernel version.
Change-Id: I26aec5afbbd4f4a1f5fd900912545b6f5050de64
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
diff --git a/wpa_supplicant/bgscan_learn.c b/wpa_supplicant/bgscan_learn.c
new file mode 100644
index 0000000..ee79511
--- /dev/null
+++ b/wpa_supplicant/bgscan_learn.c
@@ -0,0 +1,614 @@
+/*
+ * WPA Supplicant - background scan and roaming module: learn
+ * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
+ *
+ * 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 "includes.h"
+
+#include "common.h"
+#include "eloop.h"
+#include "list.h"
+#include "common/ieee802_11_defs.h"
+#include "drivers/driver.h"
+#include "config_ssid.h"
+#include "wpa_supplicant_i.h"
+#include "driver_i.h"
+#include "scan.h"
+#include "bgscan.h"
+
+struct bgscan_learn_bss {
+ struct dl_list list;
+ u8 bssid[ETH_ALEN];
+ int freq;
+ u8 *neigh; /* num_neigh * ETH_ALEN buffer */
+ size_t num_neigh;
+};
+
+struct bgscan_learn_data {
+ struct wpa_supplicant *wpa_s;
+ const struct wpa_ssid *ssid;
+ int scan_interval;
+ int signal_threshold;
+ int short_interval; /* use if signal < threshold */
+ int long_interval; /* use if signal > threshold */
+ struct os_time last_bgscan;
+ char *fname;
+ struct dl_list bss;
+ int *supp_freqs;
+ int probe_idx;
+};
+
+
+static void bss_free(struct bgscan_learn_bss *bss)
+{
+ os_free(bss->neigh);
+ os_free(bss);
+}
+
+
+static int bssid_in_array(u8 *array, size_t array_len, const u8 *bssid)
+{
+ size_t i;
+
+ if (array == NULL || array_len == 0)
+ return 0;
+
+ for (i = 0; i < array_len; i++) {
+ if (os_memcmp(array + i * ETH_ALEN, bssid, ETH_ALEN) == 0)
+ return 1;
+ }
+
+ return 0;
+}
+
+
+static void bgscan_learn_add_neighbor(struct bgscan_learn_bss *bss,
+ const u8 *bssid)
+{
+ u8 *n;
+
+ if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
+ return;
+ if (bssid_in_array(bss->neigh, bss->num_neigh, bssid))
+ return;
+
+ n = os_realloc(bss->neigh, (bss->num_neigh + 1) * ETH_ALEN);
+ if (n == NULL)
+ return;
+
+ os_memcpy(n + bss->num_neigh * ETH_ALEN, bssid, ETH_ALEN);
+ bss->neigh = n;
+ bss->num_neigh++;
+}
+
+
+static struct bgscan_learn_bss * bgscan_learn_get_bss(
+ struct bgscan_learn_data *data, const u8 *bssid)
+{
+ struct bgscan_learn_bss *bss;
+
+ dl_list_for_each(bss, &data->bss, struct bgscan_learn_bss, list) {
+ if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
+ return bss;
+ }
+ return NULL;
+}
+
+
+static int bgscan_learn_load(struct bgscan_learn_data *data)
+{
+ FILE *f;
+ char buf[128];
+ struct bgscan_learn_bss *bss;
+
+ if (data->fname == NULL)
+ return 0;
+
+ f = fopen(data->fname, "r");
+ if (f == NULL)
+ return 0;
+
+ wpa_printf(MSG_DEBUG, "bgscan learn: Loading data from %s",
+ data->fname);
+
+ if (fgets(buf, sizeof(buf), f) == NULL ||
+ os_strncmp(buf, "wpa_supplicant-bgscan-learn\n", 28) != 0) {
+ wpa_printf(MSG_INFO, "bgscan learn: Invalid data file %s",
+ data->fname);
+ fclose(f);
+ return -1;
+ }
+
+ while (fgets(buf, sizeof(buf), f)) {
+ if (os_strncmp(buf, "BSS ", 4) == 0) {
+ bss = os_zalloc(sizeof(*bss));
+ if (!bss)
+ continue;
+ if (hwaddr_aton(buf + 4, bss->bssid) < 0) {
+ bss_free(bss);
+ continue;
+ }
+ bss->freq = atoi(buf + 4 + 18);
+ dl_list_add(&data->bss, &bss->list);
+ wpa_printf(MSG_DEBUG, "bgscan learn: Loaded BSS "
+ "entry: " MACSTR " freq=%d",
+ MAC2STR(bss->bssid), bss->freq);
+ }
+
+ if (os_strncmp(buf, "NEIGHBOR ", 9) == 0) {
+ u8 addr[ETH_ALEN];
+
+ if (hwaddr_aton(buf + 9, addr) < 0)
+ continue;
+ bss = bgscan_learn_get_bss(data, addr);
+ if (bss == NULL)
+ continue;
+ if (hwaddr_aton(buf + 9 + 18, addr) < 0)
+ continue;
+
+ bgscan_learn_add_neighbor(bss, addr);
+ }
+ }
+
+ fclose(f);
+ return 0;
+}
+
+
+static void bgscan_learn_save(struct bgscan_learn_data *data)
+{
+ FILE *f;
+ struct bgscan_learn_bss *bss;
+
+ if (data->fname == NULL)
+ return;
+
+ wpa_printf(MSG_DEBUG, "bgscan learn: Saving data to %s",
+ data->fname);
+
+ f = fopen(data->fname, "w");
+ if (f == NULL)
+ return;
+ fprintf(f, "wpa_supplicant-bgscan-learn\n");
+
+ dl_list_for_each(bss, &data->bss, struct bgscan_learn_bss, list) {
+ fprintf(f, "BSS " MACSTR " %d\n",
+ MAC2STR(bss->bssid), bss->freq);
+ }
+
+ dl_list_for_each(bss, &data->bss, struct bgscan_learn_bss, list) {
+ size_t i;
+ for (i = 0; i < bss->num_neigh; i++) {
+ fprintf(f, "NEIGHBOR " MACSTR " " MACSTR "\n",
+ MAC2STR(bss->bssid),
+ MAC2STR(bss->neigh + i * ETH_ALEN));
+ }
+ }
+
+ fclose(f);
+}
+
+
+static int in_array(int *array, int val)
+{
+ int i;
+
+ if (array == NULL)
+ return 0;
+
+ for (i = 0; array[i]; i++) {
+ if (array[i] == val)
+ return 1;
+ }
+
+ return 0;
+}
+
+
+static int * bgscan_learn_get_freqs(struct bgscan_learn_data *data,
+ size_t *count)
+{
+ struct bgscan_learn_bss *bss;
+ int *freqs = NULL, *n;
+
+ *count = 0;
+
+ dl_list_for_each(bss, &data->bss, struct bgscan_learn_bss, list) {
+ if (in_array(freqs, bss->freq))
+ continue;
+ n = os_realloc(freqs, (*count + 2) * sizeof(int));
+ if (n == NULL)
+ return freqs;
+ freqs = n;
+ freqs[*count] = bss->freq;
+ (*count)++;
+ freqs[*count] = 0;
+ }
+
+ return freqs;
+}
+
+
+static int * bgscan_learn_get_probe_freq(struct bgscan_learn_data *data,
+ int *freqs, size_t count)
+{
+ int idx, *n;
+
+ if (data->supp_freqs == NULL)
+ return freqs;
+
+ idx = data->probe_idx + 1;
+ while (idx != data->probe_idx) {
+ if (data->supp_freqs[idx] == 0)
+ idx = 0;
+ if (!in_array(freqs, data->supp_freqs[idx])) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Probe new freq "
+ "%u", data->supp_freqs[idx]);
+ data->probe_idx = idx;
+ n = os_realloc(freqs, (count + 2) * sizeof(int));
+ if (n == NULL)
+ return freqs;
+ freqs = n;
+ freqs[count] = data->supp_freqs[idx];
+ count++;
+ freqs[count] = 0;
+ break;
+ }
+
+ idx++;
+ }
+
+ return freqs;
+}
+
+
+static void bgscan_learn_timeout(void *eloop_ctx, void *timeout_ctx)
+{
+ struct bgscan_learn_data *data = eloop_ctx;
+ struct wpa_supplicant *wpa_s = data->wpa_s;
+ struct wpa_driver_scan_params params;
+ int *freqs = NULL;
+ size_t count, i;
+ char msg[100], *pos;
+
+ os_memset(¶ms, 0, sizeof(params));
+ params.num_ssids = 1;
+ params.ssids[0].ssid = data->ssid->ssid;
+ params.ssids[0].ssid_len = data->ssid->ssid_len;
+ if (data->ssid->scan_freq)
+ params.freqs = data->ssid->scan_freq;
+ else {
+ freqs = bgscan_learn_get_freqs(data, &count);
+ wpa_printf(MSG_DEBUG, "bgscan learn: BSSes in this ESS have "
+ "been seen on %u channels", (unsigned int) count);
+ freqs = bgscan_learn_get_probe_freq(data, freqs, count);
+
+ msg[0] = '\0';
+ pos = msg;
+ for (i = 0; freqs && freqs[i]; i++) {
+ int ret;
+ ret = os_snprintf(pos, msg + sizeof(msg) - pos, " %d",
+ freqs[i]);
+ if (ret < 0 || ret >= msg + sizeof(msg) - pos)
+ break;
+ pos += ret;
+ }
+ pos[0] = '\0';
+ wpa_printf(MSG_DEBUG, "bgscan learn: Scanning frequencies:%s",
+ msg);
+ params.freqs = freqs;
+ }
+
+ wpa_printf(MSG_DEBUG, "bgscan learn: Request a background scan");
+ if (wpa_supplicant_trigger_scan(wpa_s, ¶ms)) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Failed to trigger scan");
+ eloop_register_timeout(data->scan_interval, 0,
+ bgscan_learn_timeout, data, NULL);
+ } else
+ os_get_time(&data->last_bgscan);
+ os_free(freqs);
+}
+
+
+static int bgscan_learn_get_params(struct bgscan_learn_data *data,
+ const char *params)
+{
+ const char *pos;
+
+ if (params == NULL)
+ return 0;
+
+ data->short_interval = atoi(params);
+
+ pos = os_strchr(params, ':');
+ if (pos == NULL)
+ return 0;
+ pos++;
+ data->signal_threshold = atoi(pos);
+ pos = os_strchr(pos, ':');
+ if (pos == NULL) {
+ wpa_printf(MSG_ERROR, "bgscan learn: Missing scan interval "
+ "for high signal");
+ return -1;
+ }
+ pos++;
+ data->long_interval = atoi(pos);
+ pos = os_strchr(pos, ':');
+ if (pos) {
+ pos++;
+ data->fname = os_strdup(pos);
+ }
+
+ return 0;
+}
+
+
+static int * bgscan_learn_get_supp_freqs(struct wpa_supplicant *wpa_s)
+{
+ struct hostapd_hw_modes *modes;
+ u16 num_modes, flags;
+ int i, j, *freqs = NULL, *n;
+ size_t count = 0;
+
+ modes = wpa_drv_get_hw_feature_data(wpa_s, &num_modes, &flags);
+ if (!modes)
+ return NULL;
+
+ for (i = 0; i < num_modes; i++) {
+ for (j = 0; j < modes[i].num_channels; j++) {
+ if (modes[i].channels[j].flag & HOSTAPD_CHAN_DISABLED)
+ continue;
+ n = os_realloc(freqs, (count + 2) * sizeof(int));
+ if (!n)
+ continue;
+
+ freqs = n;
+ freqs[count] = modes[i].channels[j].freq;
+ count++;
+ freqs[count] = 0;
+ }
+ os_free(modes[i].channels);
+ os_free(modes[i].rates);
+ }
+ os_free(modes);
+
+ return freqs;
+}
+
+
+static void * bgscan_learn_init(struct wpa_supplicant *wpa_s,
+ const char *params,
+ const struct wpa_ssid *ssid)
+{
+ struct bgscan_learn_data *data;
+
+ data = os_zalloc(sizeof(*data));
+ if (data == NULL)
+ return NULL;
+ dl_list_init(&data->bss);
+ data->wpa_s = wpa_s;
+ data->ssid = ssid;
+ if (bgscan_learn_get_params(data, params) < 0) {
+ os_free(data->fname);
+ os_free(data);
+ return NULL;
+ }
+ if (data->short_interval <= 0)
+ data->short_interval = 30;
+ if (data->long_interval <= 0)
+ data->long_interval = 30;
+
+ if (bgscan_learn_load(data) < 0) {
+ os_free(data->fname);
+ os_free(data);
+ return NULL;
+ }
+
+ wpa_printf(MSG_DEBUG, "bgscan learn: Signal strength threshold %d "
+ "Short bgscan interval %d Long bgscan interval %d",
+ data->signal_threshold, data->short_interval,
+ data->long_interval);
+
+ if (data->signal_threshold &&
+ wpa_drv_signal_monitor(wpa_s, data->signal_threshold, 4) < 0) {
+ wpa_printf(MSG_ERROR, "bgscan learn: Failed to enable "
+ "signal strength monitoring");
+ }
+
+ data->supp_freqs = bgscan_learn_get_supp_freqs(wpa_s);
+ data->scan_interval = data->short_interval;
+ eloop_register_timeout(data->scan_interval, 0, bgscan_learn_timeout,
+ data, NULL);
+
+ /*
+ * This function is called immediately after an association, so it is
+ * reasonable to assume that a scan was completed recently. This makes
+ * us skip an immediate new scan in cases where the current signal
+ * level is below the bgscan threshold.
+ */
+ os_get_time(&data->last_bgscan);
+
+ return data;
+}
+
+
+static void bgscan_learn_deinit(void *priv)
+{
+ struct bgscan_learn_data *data = priv;
+ struct bgscan_learn_bss *bss, *n;
+
+ bgscan_learn_save(data);
+ eloop_cancel_timeout(bgscan_learn_timeout, data, NULL);
+ if (data->signal_threshold)
+ wpa_drv_signal_monitor(data->wpa_s, 0, 0);
+ os_free(data->fname);
+ dl_list_for_each_safe(bss, n, &data->bss, struct bgscan_learn_bss,
+ list) {
+ dl_list_del(&bss->list);
+ bss_free(bss);
+ }
+ os_free(data->supp_freqs);
+ os_free(data);
+}
+
+
+static int bgscan_learn_bss_match(struct bgscan_learn_data *data,
+ struct wpa_scan_res *bss)
+{
+ const u8 *ie;
+
+ ie = wpa_scan_get_ie(bss, WLAN_EID_SSID);
+ if (ie == NULL)
+ return 0;
+
+ if (data->ssid->ssid_len != ie[1] ||
+ os_memcmp(data->ssid->ssid, ie + 2, ie[1]) != 0)
+ return 0; /* SSID mismatch */
+
+ return 1;
+}
+
+
+static int bgscan_learn_notify_scan(void *priv,
+ struct wpa_scan_results *scan_res)
+{
+ struct bgscan_learn_data *data = priv;
+ size_t i, j;
+#define MAX_BSS 50
+ u8 bssid[MAX_BSS * ETH_ALEN];
+ size_t num_bssid = 0;
+
+ wpa_printf(MSG_DEBUG, "bgscan learn: scan result notification");
+
+ eloop_cancel_timeout(bgscan_learn_timeout, data, NULL);
+ eloop_register_timeout(data->scan_interval, 0, bgscan_learn_timeout,
+ data, NULL);
+
+ for (i = 0; i < scan_res->num; i++) {
+ struct wpa_scan_res *res = scan_res->res[i];
+ if (!bgscan_learn_bss_match(data, res))
+ continue;
+
+ if (num_bssid < MAX_BSS) {
+ os_memcpy(bssid + num_bssid * ETH_ALEN, res->bssid,
+ ETH_ALEN);
+ num_bssid++;
+ }
+ }
+ wpa_printf(MSG_DEBUG, "bgscan learn: %u matching BSSes in scan "
+ "results", (unsigned int) num_bssid);
+
+ for (i = 0; i < scan_res->num; i++) {
+ struct wpa_scan_res *res = scan_res->res[i];
+ struct bgscan_learn_bss *bss;
+
+ if (!bgscan_learn_bss_match(data, res))
+ continue;
+
+ bss = bgscan_learn_get_bss(data, res->bssid);
+ if (bss && bss->freq != res->freq) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Update BSS "
+ MACSTR " freq %d -> %d",
+ MAC2STR(res->bssid), bss->freq, res->freq);
+ bss->freq = res->freq;
+ } else if (!bss) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Add BSS " MACSTR
+ " freq=%d", MAC2STR(res->bssid), res->freq);
+ bss = os_zalloc(sizeof(*bss));
+ if (!bss)
+ continue;
+ os_memcpy(bss->bssid, res->bssid, ETH_ALEN);
+ bss->freq = res->freq;
+ dl_list_add(&data->bss, &bss->list);
+ }
+
+ for (j = 0; j < num_bssid; j++) {
+ u8 *addr = bssid + j * ETH_ALEN;
+ bgscan_learn_add_neighbor(bss, addr);
+ }
+ }
+
+ /*
+ * A more advanced bgscan could process scan results internally, select
+ * the BSS and request roam if needed. This sample uses the existing
+ * BSS/ESS selection routine. Change this to return 1 if selection is
+ * done inside the bgscan module.
+ */
+
+ return 0;
+}
+
+
+static void bgscan_learn_notify_beacon_loss(void *priv)
+{
+ wpa_printf(MSG_DEBUG, "bgscan learn: beacon loss");
+ /* TODO: speed up background scanning */
+}
+
+
+static void bgscan_learn_notify_signal_change(void *priv, int above,
+ int current_signal,
+ int current_noise,
+ int current_txrate)
+{
+ struct bgscan_learn_data *data = priv;
+ int scan = 0;
+ struct os_time now;
+
+ if (data->short_interval == data->long_interval ||
+ data->signal_threshold == 0)
+ return;
+
+ wpa_printf(MSG_DEBUG, "bgscan learn: signal level changed "
+ "(above=%d current_signal=%d current_noise=%d "
+ "current_txrate=%d)", above, current_signal,
+ current_noise, current_txrate);
+ if (data->scan_interval == data->long_interval && !above) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Start using short bgscan "
+ "interval");
+ data->scan_interval = data->short_interval;
+ os_get_time(&now);
+ if (now.sec > data->last_bgscan.sec + 1)
+ scan = 1;
+ } else if (data->scan_interval == data->short_interval && above) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Start using long bgscan "
+ "interval");
+ data->scan_interval = data->long_interval;
+ eloop_cancel_timeout(bgscan_learn_timeout, data, NULL);
+ eloop_register_timeout(data->scan_interval, 0,
+ bgscan_learn_timeout, data, NULL);
+ } else if (!above) {
+ /*
+ * Signal dropped further 4 dB. Request a new scan if we have
+ * not yet scanned in a while.
+ */
+ os_get_time(&now);
+ if (now.sec > data->last_bgscan.sec + 10)
+ scan = 1;
+ }
+
+ if (scan) {
+ wpa_printf(MSG_DEBUG, "bgscan learn: Trigger immediate scan");
+ eloop_cancel_timeout(bgscan_learn_timeout, data, NULL);
+ eloop_register_timeout(0, 0, bgscan_learn_timeout, data, NULL);
+ }
+}
+
+
+const struct bgscan_ops bgscan_learn_ops = {
+ .name = "learn",
+ .init = bgscan_learn_init,
+ .deinit = bgscan_learn_deinit,
+ .notify_scan = bgscan_learn_notify_scan,
+ .notify_beacon_loss = bgscan_learn_notify_beacon_loss,
+ .notify_signal_change = bgscan_learn_notify_signal_change,
+};