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>

1 files changed, 614 insertions, 0 deletions

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(&params, 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, &params)) {
+		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,
+};