driver_wext.c

IEEE802.11 a/b/g 客户端应用程序源代码

	return *i;
}

#endif /* CONFIG_CLIENT_MLME */


/**
 * wpa_driver_wext_set_ifflags - Set interface flags (SIOCSIFFLAGS)
 * @drv: driver_wext private data
 * @flags: New value for flags
 * Returns: 0 on success, -1 on failure
 */
int wpa_driver_wext_set_ifflags(struct wpa_driver_wext_data *drv, int flags)
{
	return wpa_driver_wext_set_ifflags_ifname(drv, drv->ifname, flags);
}


/**
 * wpa_driver_wext_init - Initialize WE driver interface
 * @ctx: context to be used when calling wpa_supplicant functions,
 * e.g., wpa_supplicant_event()
 * @ifname: interface name, e.g., wlan0
 * Returns: Pointer to private data, %NULL on failure
 */
void * wpa_driver_wext_init(void *ctx, const char *ifname)
{
	int s;
	struct sockaddr_nl local;
	struct wpa_driver_wext_data *drv;

	drv = os_zalloc(sizeof(*drv));
	if (drv == NULL)
		return NULL;
	drv->ctx = ctx;
	os_strlcpy(drv->ifname, ifname, sizeof(drv->ifname));

	drv->ioctl_sock = socket(PF_INET, SOCK_DGRAM, 0);
	if (drv->ioctl_sock < 0) {
		perror("socket(PF_INET,SOCK_DGRAM)");
		os_free(drv);
		return NULL;
	}

	s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	if (s < 0) {
		perror("socket(PF_NETLINK,SOCK_RAW,NETLINK_ROUTE)");
		close(drv->ioctl_sock);
		os_free(drv);
		return NULL;
	}

	os_memset(&local, 0, sizeof(local));
	local.nl_family = AF_NETLINK;
	local.nl_groups = RTMGRP_LINK;
	if (bind(s, (struct sockaddr *) &local, sizeof(local)) < 0) {
		perror("bind(netlink)");
		close(s);
		close(drv->ioctl_sock);
		os_free(drv);
		return NULL;
	}

	eloop_register_read_sock(s, wpa_driver_wext_event_receive, drv, ctx);
	drv->event_sock = s;

	drv->mlme_sock = -1;

	wpa_driver_wext_finish_drv_init(drv);

	return drv;
}


static void wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv)
{
	int flags;

	if (wpa_driver_wext_get_ifflags(drv, &flags) != 0)
		printf("Could not get interface '%s' flags\n", drv->ifname);
	else if (!(flags & IFF_UP)) {
		if (wpa_driver_wext_set_ifflags(drv, flags | IFF_UP) != 0) {
			printf("Could not set interface '%s' UP\n",
			       drv->ifname);
		} else {
			/*
			 * Wait some time to allow driver to initialize before
			 * starting configuring the driver. This seems to be
			 * needed at least some drivers that load firmware etc.
			 * when the interface is set up.
			 */
			wpa_printf(MSG_DEBUG, "Interface %s set UP - waiting "
				   "a second for the driver to complete "
				   "initialization", drv->ifname);
			sleep(1);
		}
	}

	/*
	 * Make sure that the driver does not have any obsolete PMKID entries.
	 */
	wpa_driver_wext_flush_pmkid(drv);

	if (wpa_driver_wext_set_mode(drv, 0) < 0) {
		printf("Could not configure driver to use managed mode\n");
	}

	wpa_driver_wext_get_range(drv);

	drv->ifindex = if_nametoindex(drv->ifname);

	if (os_strncmp(drv->ifname, "wlan", 4) == 0) {
		/*
		 * Host AP driver may use both wlan# and wifi# interface in
		 * wireless events. Since some of the versions included WE-18
		 * support, let's add the alternative ifindex also from
		 * driver_wext.c for the time being. This may be removed at
		 * some point once it is believed that old versions of the
		 * driver are not in use anymore.
		 */
		char ifname2[IFNAMSIZ + 1];
		os_strlcpy(ifname2, drv->ifname, sizeof(ifname2));
		os_memcpy(ifname2, "wifi", 4);
		wpa_driver_wext_alternative_ifindex(drv, ifname2);
	}

	wpa_driver_wext_send_oper_ifla(drv, 1, IF_OPER_DORMANT);
}


/**
 * wpa_driver_wext_deinit - Deinitialize WE driver interface
 * @priv: Pointer to private wext data from wpa_driver_wext_init()
 *
 * Shut down driver interface and processing of driver events. Free
 * private data buffer if one was allocated in wpa_driver_wext_init().
 */
void wpa_driver_wext_deinit(void *priv)
{
	struct wpa_driver_wext_data *drv = priv;
	int flags;

	eloop_cancel_timeout(wpa_driver_wext_scan_timeout, drv, drv->ctx);

	/*
	 * Clear possibly configured driver parameters in order to make it
	 * easier to use the driver after wpa_supplicant has been terminated.
	 */
	(void) wpa_driver_wext_set_bssid(drv,
					 (u8 *) "\x00\x00\x00\x00\x00\x00");

	wpa_driver_wext_send_oper_ifla(priv, 0, IF_OPER_UP);

	eloop_unregister_read_sock(drv->event_sock);
	if (drv->mlme_sock >= 0)
		eloop_unregister_read_sock(drv->mlme_sock);

	if (wpa_driver_wext_get_ifflags(drv, &flags) == 0)
		(void) wpa_driver_wext_set_ifflags(drv, flags & ~IFF_UP);

#ifdef CONFIG_CLIENT_MLME
	if (drv->mlmedev[0]) {
		if (wpa_driver_wext_get_ifflags_ifname(drv, drv->mlmedev,
						       &flags) == 0)
			(void) wpa_driver_wext_set_ifflags_ifname(
				drv, drv->mlmedev, flags & ~IFF_UP);
		wpa_driver_prism2_param_set(drv, PRISM2_PARAM_MGMT_IF, 0);
		wpa_driver_prism2_param_set(drv, PRISM2_PARAM_USER_SPACE_MLME,
					    0);
	}
#endif /* CONFIG_CLIENT_MLME */

	close(drv->event_sock);
	close(drv->ioctl_sock);
	if (drv->mlme_sock >= 0)
		close(drv->mlme_sock);
	os_free(drv->assoc_req_ies);
	os_free(drv->assoc_resp_ies);
	os_free(drv);
}


/**
 * wpa_driver_wext_scan_timeout - Scan timeout to report scan completion
 * @eloop_ctx: Unused
 * @timeout_ctx: ctx argument given to wpa_driver_wext_init()
 *
 * This function can be used as registered timeout when starting a scan to
 * generate a scan completed event if the driver does not report this.
 */
void wpa_driver_wext_scan_timeout(void *eloop_ctx, void *timeout_ctx)
{
	wpa_printf(MSG_DEBUG, "Scan timeout - try to get results");
	wpa_supplicant_event(timeout_ctx, EVENT_SCAN_RESULTS, NULL);
}


/**
 * wpa_driver_wext_scan - Request the driver to initiate scan
 * @priv: Pointer to private wext data from wpa_driver_wext_init()
 * @ssid: Specific SSID to scan for (ProbeReq) or %NULL to scan for
 *	all SSIDs (either active scan with broadcast SSID or passive
 *	scan
 * @ssid_len: Length of the SSID
 * Returns: 0 on success, -1 on failure
 */
int wpa_driver_wext_scan(void *priv, const u8 *ssid, size_t ssid_len)
{
	struct wpa_driver_wext_data *drv = priv;
	struct iwreq iwr;
	int ret = 0, timeout;
	struct iw_scan_req req;

	if (ssid_len > IW_ESSID_MAX_SIZE) {
		wpa_printf(MSG_DEBUG, "%s: too long SSID (%lu)",
			   __FUNCTION__, (unsigned long) ssid_len);
		return -1;
	}

	os_memset(&iwr, 0, sizeof(iwr));
	os_strlcpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);

	if (ssid && ssid_len) {
		os_memset(&req, 0, sizeof(req));
		req.essid_len = ssid_len;
		req.bssid.sa_family = ARPHRD_ETHER;
		os_memset(req.bssid.sa_data, 0xff, ETH_ALEN);
		os_memcpy(req.essid, ssid, ssid_len);
		iwr.u.data.pointer = (caddr_t) &req;
		iwr.u.data.length = sizeof(req);
		iwr.u.data.flags = IW_SCAN_THIS_ESSID;
	}

	if (ioctl(drv->ioctl_sock, SIOCSIWSCAN, &iwr) < 0) {
		perror("ioctl[SIOCSIWSCAN]");
		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_wext_scan_timeout, drv, drv->ctx);
	eloop_register_timeout(timeout, 0, wpa_driver_wext_scan_timeout, drv,
			       drv->ctx);

	return ret;
}


static u8 * wpa_driver_wext_giwscan(struct wpa_driver_wext_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);
	}