driver_nl80211.c

IEEE802.11 a/b/g 客户端应用程序源代码

		ret = -1;
	}

	/* Not all drivers generate "scan completed" wireless event, so try to
	 * read results after a timeout. */
	timeout = 5;
	if (drv->scan_complete_events) {
		/*
		 * The driver seems to deliver SIOCGIWSCAN events to notify
		 * when scan is complete, so use longer timeout to avoid race
		 * conditions with scanning and following association request.
		 */
		timeout = 30;
	}
	wpa_printf(MSG_DEBUG, "Scan requested (ret=%d) - scan timeout %d "
		   "seconds", ret, timeout);
	eloop_cancel_timeout(wpa_driver_nl80211_scan_timeout, drv, drv->ctx);
	eloop_register_timeout(timeout, 0, wpa_driver_nl80211_scan_timeout, drv,
			       drv->ctx);

	return ret;
}


static u8 * wpa_driver_nl80211_giwscan(struct wpa_driver_nl80211_data *drv,
				    size_t *len)
{
	struct iwreq iwr;
	u8 *res_buf;
	size_t res_buf_len;

	res_buf_len = IW_SCAN_MAX_DATA;
	for (;;) {
		res_buf = os_malloc(res_buf_len);
		if (res_buf == NULL)
			return NULL;
		os_memset(&iwr, 0, sizeof(iwr));
		os_strlcpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
		iwr.u.data.pointer = res_buf;
		iwr.u.data.length = res_buf_len;

		if (ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr) == 0)
			break;

		if (errno == E2BIG && res_buf_len < 100000) {
			os_free(res_buf);
			res_buf = NULL;
			res_buf_len *= 2;
			wpa_printf(MSG_DEBUG, "Scan results did not fit - "
				   "trying larger buffer (%lu bytes)",
				   (unsigned long) res_buf_len);
		} else {
			perror("ioctl[SIOCGIWSCAN]");
			os_free(res_buf);
			return NULL;
		}
	}

	if (iwr.u.data.length > res_buf_len) {
		os_free(res_buf);
		return NULL;
	}
	*len = iwr.u.data.length;

	return res_buf;
}


/*
 * Data structure for collecting WEXT scan results. This is needed to allow
 * the various methods of reporting IEs to be combined into a single IE buffer.
 */
struct wext_scan_data {
	struct wpa_scan_res res;
	u8 *ie;
	size_t ie_len;
	u8 ssid[32];
	size_t ssid_len;
	int maxrate;
};


static void wext_get_scan_mode(struct iw_event *iwe,
			       struct wext_scan_data *res)
{
	if (iwe->u.mode == IW_MODE_ADHOC)
		res->res.caps |= IEEE80211_CAP_IBSS;
	else if (iwe->u.mode == IW_MODE_MASTER || iwe->u.mode == IW_MODE_INFRA)
		res->res.caps |= IEEE80211_CAP_ESS;
}


static void wext_get_scan_ssid(struct iw_event *iwe,
			       struct wext_scan_data *res, char *custom,
			       char *end)
{
	int ssid_len = iwe->u.essid.length;
	if (custom + ssid_len > end)
		return;
	if (iwe->u.essid.flags &&
	    ssid_len > 0 &&
	    ssid_len <= IW_ESSID_MAX_SIZE) {
		os_memcpy(res->ssid, custom, ssid_len);
		res->ssid_len = ssid_len;
	}
}


static void wext_get_scan_freq(struct iw_event *iwe,
			       struct wext_scan_data *res)
{
	int divi = 1000000, i;

	if (iwe->u.freq.e == 0) {
		/*
		 * Some drivers do not report frequency, but a channel.
		 * Try to map this to frequency by assuming they are using
		 * IEEE 802.11b/g.  But don't overwrite a previously parsed
		 * frequency if the driver sends both frequency and channel,
		 * since the driver may be sending an A-band channel that we
		 * don't handle here.
		 */

		if (res->res.freq)
			return;

		if (iwe->u.freq.m >= 1 && iwe->u.freq.m <= 13) {
			res->res.freq = 2407 + 5 * iwe->u.freq.m;
			return;
		} else if (iwe->u.freq.m == 14) {
			res->res.freq = 2484;
			return;
		}
	}

	if (iwe->u.freq.e > 6) {
		wpa_printf(MSG_DEBUG, "Invalid freq in scan results (BSSID="
			   MACSTR " m=%d e=%d)",
			   MAC2STR(res->res.bssid), iwe->u.freq.m,
			   iwe->u.freq.e);
		return;
	}

	for (i = 0; i < iwe->u.freq.e; i++)
		divi /= 10;
	res->res.freq = iwe->u.freq.m / divi;
}


static void wext_get_scan_qual(struct iw_event *iwe,
			       struct wext_scan_data *res)
{
	res->res.qual = iwe->u.qual.qual;
	res->res.noise = iwe->u.qual.noise;
	res->res.level = iwe->u.qual.level;
}


static void wext_get_scan_encode(struct iw_event *iwe,
				 struct wext_scan_data *res)
{
	if (!(iwe->u.data.flags & IW_ENCODE_DISABLED))
		res->res.caps |= IEEE80211_CAP_PRIVACY;
}


static void wext_get_scan_rate(struct iw_event *iwe,
			       struct wext_scan_data *res, char *pos,
			       char *end)
{
	int maxrate;
	char *custom = pos + IW_EV_LCP_LEN;
	struct iw_param p;
	size_t clen;

	clen = iwe->len;
	if (custom + clen > end)
		return;
	maxrate = 0;
	while (((ssize_t) clen) >= (ssize_t) sizeof(struct iw_param)) {
		/* Note: may be misaligned, make a local, aligned copy */
		os_memcpy(&p, custom, sizeof(struct iw_param));
		if (p.value > maxrate)
			maxrate = p.value;
		clen -= sizeof(struct iw_param);
		custom += sizeof(struct iw_param);
	}

	/* Convert the maxrate from WE-style (b/s units) to
	 * 802.11 rates (500000 b/s units).
	 */
	res->maxrate = maxrate / 500000;
}


static void wext_get_scan_iwevgenie(struct iw_event *iwe,
				    struct wext_scan_data *res, char *custom,
				    char *end)
{
	char *genie, *gpos, *gend;
	u8 *tmp;

	gpos = genie = custom;
	gend = genie + iwe->u.data.length;
	if (gend > end) {
		wpa_printf(MSG_INFO, "IWEVGENIE overflow");
		return;
	}

	tmp = os_realloc(res->ie, res->ie_len + gend - gpos);
	if (tmp == NULL)
		return;
	os_memcpy(tmp + res->ie_len, gpos, gend - gpos);
	res->ie = tmp;
	res->ie_len += gend - gpos;
}


static void wext_get_scan_custom(struct iw_event *iwe,
				 struct wext_scan_data *res, char *custom,
				 char *end)
{
	size_t clen;
	u8 *tmp;

	clen = iwe->u.data.length;
	if (custom + clen > end)
		return;

	if (clen > 7 && os_strncmp(custom, "wpa_ie=", 7) == 0) {
		char *spos;
		int bytes;
		spos = custom + 7;
		bytes = custom + clen - spos;
		if (bytes & 1)
			return;
		bytes /= 2;
		tmp = os_realloc(res->ie, res->ie_len + bytes);
		if (tmp == NULL)
			return;
		hexstr2bin(spos, tmp + res->ie_len, bytes);
		res->ie = tmp;
		res->ie_len += bytes;
	} else if (clen > 7 && os_strncmp(custom, "rsn_ie=", 7) == 0) {
		char *spos;
		int bytes;
		spos = custom + 7;
		bytes = custom + clen - spos;
		if (bytes & 1)
			return;
		bytes /= 2;
		tmp = os_realloc(res->ie, res->ie_len + bytes);
		if (tmp == NULL)
			return;
		hexstr2bin(spos, tmp + res->ie_len, bytes);
		res->ie = tmp;
		res->ie_len += bytes;
	} else if (clen > 4 && os_strncmp(custom, "tsf=", 4) == 0) {
		char *spos;
		int bytes;
		u8 bin[8];
		spos = custom + 4;
		bytes = custom + clen - spos;
		if (bytes != 16) {
			wpa_printf(MSG_INFO, "Invalid TSF length (%d)", bytes);
			return;
		}
		bytes /= 2;
		hexstr2bin(spos, bin, bytes);
		res->res.tsf += WPA_GET_BE64(bin);
	}
}


static int wext_19_iw_point(struct wpa_driver_nl80211_data *drv, u16 cmd)
{
	return drv->we_version_compiled > 18 &&
		(cmd == SIOCGIWESSID || cmd == SIOCGIWENCODE ||
		 cmd == IWEVGENIE || cmd == IWEVCUSTOM);
}


static void wpa_driver_nl80211_add_scan_entry(struct wpa_scan_results *res,
					   struct wext_scan_data *data)
{
	struct wpa_scan_res **tmp;
	struct wpa_scan_res *r;
	size_t extra_len;
	u8 *pos, *end, *ssid_ie = NULL, *rate_ie = NULL;

	/* Figure out whether we need to fake any IEs */
	pos = data->ie;
	end = pos + data->ie_len;
	while (pos && pos + 1 < end) {
		if (pos + 2 + pos[1] > end)
			break;
		if (pos[0] == WLAN_EID_SSID)
			ssid_ie = pos;
		else if (pos[0] == WLAN_EID_SUPP_RATES)
			rate_ie = pos;
		else if (pos[0] == WLAN_EID_EXT_SUPP_RATES)
			rate_ie = pos;
		pos += 2 + pos[1];
	}

	extra_len = 0;
	if (ssid_ie == NULL)
		extra_len += 2 + data->ssid_len;
	if (rate_ie == NULL && data->maxrate)
		extra_len += 3;

	r = os_zalloc(sizeof(*r) + extra_len + data->ie_len);
	if (r == NULL)
		return;
	os_memcpy(r, &data->res, sizeof(*r));
	r->ie_len = extra_len + data->ie_len;
	pos = (u8 *) (r + 1);
	if (ssid_ie == NULL) {
		/*
		 * Generate a fake SSID IE since the driver did not report
		 * a full IE list.
		 */
		*pos++ = WLAN_EID_SSID;
		*pos++ = data->ssid_len;
		os_memcpy(pos, data->ssid, data->ssid_len);
		pos += data->ssid_len;
	}
	if (rate_ie == NULL && data->maxrate) {
		/*
		 * Generate a fake Supported Rates IE since the driver did not
		 * report a full IE list.
		 */
		*pos++ = WLAN_EID_SUPP_RATES;
		*pos++ = 1;
		*pos++ = data->maxrate;
	}
	if (data->ie)
		os_memcpy(pos, data->ie, data->ie_len);

	tmp = os_realloc(res->res,
			 (res->num + 1) * sizeof(struct wpa_scan_res *));
	if (tmp == NULL) {
		os_free(r);
		return;
	}
	tmp[res->num++] = r;
	res->res = tmp;
}
				      

/**
 * wpa_driver_nl80211_get_scan_results - Fetch the latest scan results
 * @priv: Pointer to private wext data from wpa_driver_nl80211_init()
 * Returns: Scan results on success, -1 on failure
 */
struct wpa_scan_results * wpa_driver_nl80211_get_scan_results(void *priv)
{
	struct wpa_driver_nl80211_data *drv = priv;
	size_t ap_num = 0, len;
	int first;
	u8 *res_buf;
	struct iw_event iwe_buf, *iwe = &iwe_buf;
	char *pos, *end, *custom;
	struct wpa_scan_results *res;
	struct wext_scan_data data;

	res_buf = wpa_driver_nl80211_giwscan(drv, &len);
	if (res_buf == NULL)
		return NULL;

	ap_num = 0;
	first = 1;

	res = os_zalloc(sizeof(*res));
	if (res == NULL) {
		os_free(res_buf);
		return NULL;
	}

	pos = (char *) res_buf;
	end = (char *) res_buf + len;
	os_memset(&data, 0, sizeof(data));

	while (pos + IW_EV_LCP_LEN <= end) {
		/* Event data may be unaligned, so make a local, aligned copy
		 * before processing. */
		os_memcpy(&iwe_buf, pos, IW_EV_LCP_LEN);
		if (iwe->len <= IW_EV_LCP_LEN)
			break;

		custom = pos + IW_EV_POINT_LEN;
		if (wext_19_iw_point(drv, iwe->cmd)) {
			/* WE-19 removed the pointer from struct iw_point */
			char *dpos = (char *) &iwe_buf.u.data.length;
			int dlen = dpos - (char *) &iwe_buf;
			os_memcpy(dpos, pos + IW_EV_LCP_LEN,
				  sizeof(struct iw_event) - dlen);
		} else {
			os_memcpy(&iwe_buf, pos, sizeof(struct iw_event));
			custom += IW_EV_POINT_OFF;
		}

		switch (iwe->cmd) {
		case SIOCGIWAP:
			if (!first)
				wpa_driver_nl80211_add_scan_entry(res, &data);
			first = 0;
			os_free(data.ie);
			os_memset(&data, 0, sizeof(data));
			os_memcpy(data.res.bssid,
				  iwe->u.ap_addr.sa_data, ETH_ALEN);
			break;
		case SIOCGIWMODE:
			wext_get_scan_mode(iwe, &data);
			break;
		case SIOCGIWESSID:
			wext_get_scan_ssid(iwe, &data, custom, end);
			break;
		case SIOCGIWFREQ:
			wext_get_scan_freq(iwe, &data);
			break;
		case IWEVQUAL:
			wext_get_scan_qual(iwe, &data);
			break;
		case SIOCGIWENCODE:
			wext_get_scan_encode(iwe, &data);
			break;
		case SIOCGIWRATE:
			wext_get_scan_rate(iwe, &data, pos, end);
			break;
		case IWEVGENIE:
			wext_get_scan_iwevgenie(iwe, &data, custom, end);
			break;
		case IWEVCUSTOM:
			wext_get_scan_custom(iwe, &data, custom, end);
			break;
		}

		pos += iwe->len;
	}
	os_free(res_buf);
	res_buf = NULL;
	if (!first)
		wpa_driver_nl80211_add_scan_entry(res, &data);
	os_free(data.ie);

	wpa_printf(MSG_DEBUG, "Received %lu bytes of scan results (%lu BSSes)",
		   (unsigned long) len, (unsigned long) res->num);

	return res;
}


static int wpa_driver_nl80211_get_range(void *priv)
{
	struct wpa_driver_nl80211_data *drv = priv;
	struct iw_range *range;
	struct iwreq iwr;
	int minlen;
	size_t buflen;

	/*
	 * Use larger buffer than struct iw_range in order to allow the
	 * structure to grow in the future.
	 */
	buflen = sizeof(struct iw_range) + 500;
	range = os_zalloc(buflen);
	if (range == NULL)
		return -1;

	os_memset(&iwr, 0, sizeof(iwr));
	os_strlcpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	iwr.u.data.pointer = (caddr_t) range;
	iwr.u.data.length = buflen;

	minlen = ((char *) &range->enc_capa) - (char *) range +
		sizeof(range->enc_capa);

	if (ioctl(drv->ioctl_sock, SIOCGIWRANGE, &iwr) < 0) {
		perror("ioctl[SIOCGIWRANGE]");
		os_free(range);
		return -1;
	} else if (iwr.u.data.length >= minlen &&
		   range->we_version_compiled >= 18) {
		wpa_printf(MSG_DEBUG, "SIOCGIWRANGE: WE(compiled)=%d "
			   "WE(source)=%d enc_capa=0x%x",
			   range->we_version_compiled,
			   range->we_version_source,
			   range->enc_capa);
		drv->has_capability = 1;
		drv->we_version_compiled = range->we_version_compiled;
		if (range->enc_capa & IW_ENC_CAPA_WPA) {
			drv->capa.key_mgmt |= WPA_DRIVER_CAPA_KEY_MGMT_WPA |
				WPA_DRIVER_CAPA_KEY_MGMT_WPA_PSK;
		}
		if (range->enc_capa & IW_ENC_CAPA_WPA2) {
			drv->capa.key_mgmt |= WPA_DRIVER_CAPA_KEY_MGMT_WPA2 |
				WPA_DRIVER_CAPA_KEY_MGMT_WPA2_PSK;
		}
		drv->capa.enc |= WPA_DRIVER_CAPA_ENC_WEP40 |
			WPA_DRIVER_CAPA_ENC_WEP104;
		if (range->enc_capa & IW_ENC_CAPA_CIPHER_TKIP)
			drv->capa.enc |= WPA_DRIVER_CAPA_ENC_TKIP;
		if (range->enc_capa & IW_ENC_CAPA_CIPHER_CCMP)
			drv->capa.enc |= WPA_DRIVER_CAPA_ENC_CCMP;
		wpa_printf(MSG_DEBUG, "  capabilities: key_mgmt 0x%x enc 0x%x",
			   drv->capa.key_mgmt, drv->capa.enc);
	} else {
		wpa_printf(MSG_DEBUG, "SIOCGIWRANGE: too old (short) data - "
			   "assuming WPA is not supported");
	}

	os_free(range);
	return 0;
}


static int wpa_driver_nl80211_set_wpa(void *priv, int enabled)
{
	struct wpa_driver_nl80211_data *drv = priv;
	wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);

	return wpa_driver_nl80211_set_auth_param(drv, IW_AUTH_WPA_ENABLED,
					      enabled);
}