scan.c

linux内核源码

		numprobes = puserscanin->numprobes ? puserscanin->numprobes : 0;

		/*
		 * Set the BSSID filter to the incoming configuration,
		 *   if non-zero.  If not set, it will remain disabled (all zeros).
		 */
		memcpy(pscancfgout->bssid, puserscanin->bssid,
		       sizeof(pscancfgout->bssid));

		if (puserscanin->ssid_len) {
			pssidtlv =
			    (struct mrvlietypes_ssidparamset *) pscancfgout->
			    tlvbuffer;
			pssidtlv->header.type = cpu_to_le16(TLV_TYPE_SSID);
			pssidtlv->header.len = cpu_to_le16(puserscanin->ssid_len);
			memcpy(pssidtlv->ssid, puserscanin->ssid,
			       puserscanin->ssid_len);
			ptlvpos += sizeof(pssidtlv->header) + puserscanin->ssid_len;
		}

		/*
		 *  The default number of channels sent in the command is low to
		 *    ensure the response buffer from the firmware does not truncate
		 *    scan results.  That is not an issue with an SSID or BSSID
		 *    filter applied to the scan results in the firmware.
		 */
		if (   puserscanin->ssid_len
		    || (compare_ether_addr(pscancfgout->bssid, &zeromac[0]) != 0)) {
			*pmaxchanperscan = MRVDRV_MAX_CHANNELS_PER_SCAN;
			*pfilteredscan = 1;
		}
	} else {
		pscancfgout->bsstype = CMD_BSS_TYPE_ANY;
		numprobes = 0;
	}

	/* If the input config or adapter has the number of Probes set, add tlv */
	if (numprobes) {
		pnumprobestlv = (struct mrvlietypes_numprobes *) ptlvpos;
		pnumprobestlv->header.type = cpu_to_le16(TLV_TYPE_NUMPROBES);
		pnumprobestlv->header.len = cpu_to_le16(2);
		pnumprobestlv->numprobes = cpu_to_le16(numprobes);

		ptlvpos += sizeof(*pnumprobestlv);
	}

	/*
	 * Set the output for the channel TLV to the address in the tlv buffer
	 *   past any TLVs that were added in this fuction (SSID, numprobes).
	 *   channel TLVs will be added past this for each scan command, preserving
	 *   the TLVs that were previously added.
	 */
	*ppchantlvout = (struct mrvlietypes_chanlistparamset *) ptlvpos;

	if (!puserscanin || !puserscanin->chanlist[0].channumber) {
		/* Create a default channel scan list */
		lbs_deb_scan("creating full region channel list\n");
		wlan_scan_create_channel_list(priv, pscanchanlist,
					      *pfilteredscan);
		goto out;
	}

	for (chanidx = 0;
	     chanidx < WLAN_IOCTL_USER_SCAN_CHAN_MAX
	     && puserscanin->chanlist[chanidx].channumber; chanidx++) {

		channel = puserscanin->chanlist[chanidx].channumber;
		(pscanchanlist + chanidx)->channumber = channel;

		radiotype = puserscanin->chanlist[chanidx].radiotype;
		(pscanchanlist + chanidx)->radiotype = radiotype;

		scantype = puserscanin->chanlist[chanidx].scantype;

		if (scantype == CMD_SCAN_TYPE_PASSIVE) {
			(pscanchanlist +
			 chanidx)->chanscanmode.passivescan = 1;
		} else {
			(pscanchanlist +
			 chanidx)->chanscanmode.passivescan = 0;
		}

		if (puserscanin->chanlist[chanidx].scantime) {
			scandur = puserscanin->chanlist[chanidx].scantime;
		} else {
			if (scantype == CMD_SCAN_TYPE_PASSIVE) {
				scandur = MRVDRV_PASSIVE_SCAN_CHAN_TIME;
			} else {
				scandur = MRVDRV_ACTIVE_SCAN_CHAN_TIME;
			}
		}

		(pscanchanlist + chanidx)->minscantime =
		    cpu_to_le16(scandur);
		(pscanchanlist + chanidx)->maxscantime =
		    cpu_to_le16(scandur);
	}

	/* Check if we are only scanning the current channel */
	if ((chanidx == 1) &&
	    (puserscanin->chanlist[0].channumber ==
			       priv->adapter->curbssparams.channel)) {
		*pscancurrentonly = 1;
		lbs_deb_scan("scanning current channel only");
	}

out:
	return pscancfgout;
}

/**
 *  @brief Construct and send multiple scan config commands to the firmware
 *
 *  Only used from wlan_scan_networks()
 *
 *  Previous routines have created a wlan_scan_cmd_config with any requested
 *   TLVs.  This function splits the channel TLV into maxchanperscan lists
 *   and sends the portion of the channel TLV along with the other TLVs
 *   to the wlan_cmd routines for execution in the firmware.
 *
 *  @param priv            A pointer to wlan_private structure
 *  @param maxchanperscan  Maximum number channels to be included in each
 *                         scan command sent to firmware
 *  @param filteredscan    Flag indicating whether or not a BSSID or SSID
 *                         filter is being used for the firmware command
 *                         scan command sent to firmware
 *  @param pscancfgout     Scan configuration used for this scan.
 *  @param pchantlvout     Pointer in the pscancfgout where the channel TLV
 *                         should start.  This is past any other TLVs that
 *                         must be sent down in each firmware command.
 *  @param pscanchanlist   List of channels to scan in maxchanperscan segments
 *
 *  @return                0 or error return otherwise
 */
static int wlan_scan_channel_list(wlan_private * priv,
				  int maxchanperscan,
				  u8 filteredscan,
				  struct wlan_scan_cmd_config * pscancfgout,
				  struct mrvlietypes_chanlistparamset * pchantlvout,
				  struct chanscanparamset * pscanchanlist,
				  const struct wlan_ioctl_user_scan_cfg * puserscanin,
				  int full_scan)
{
	struct chanscanparamset *ptmpchan;
	struct chanscanparamset *pstartchan;
	u8 scanband;
	int doneearly;
	int tlvidx;
	int ret = 0;
	int scanned = 0;
	union iwreq_data wrqu;

	lbs_deb_enter_args(LBS_DEB_SCAN, "maxchanperscan %d, filteredscan %d, "
		"full_scan %d", maxchanperscan, filteredscan, full_scan);

	if (!pscancfgout || !pchantlvout || !pscanchanlist) {
		lbs_deb_scan("pscancfgout, pchantlvout or "
			"pscanchanlist is NULL\n");
		ret = -1;
		goto out;
	}

	pchantlvout->header.type = cpu_to_le16(TLV_TYPE_CHANLIST);

	/* Set the temp channel struct pointer to the start of the desired list */
	ptmpchan = pscanchanlist;

	if (priv->adapter->last_scanned_channel && !puserscanin)
		ptmpchan += priv->adapter->last_scanned_channel;

	/* Loop through the desired channel list, sending a new firmware scan
	 *   commands for each maxchanperscan channels (or for 1,6,11 individually
	 *   if configured accordingly)
	 */
	while (ptmpchan->channumber) {

		tlvidx = 0;
		pchantlvout->header.len = 0;
		scanband = ptmpchan->radiotype;
		pstartchan = ptmpchan;
		doneearly = 0;

		/* Construct the channel TLV for the scan command.  Continue to
		 *  insert channel TLVs until:
		 *    - the tlvidx hits the maximum configured per scan command
		 *    - the next channel to insert is 0 (end of desired channel list)
		 *    - doneearly is set (controlling individual scanning of 1,6,11)
		 */
		while (tlvidx < maxchanperscan && ptmpchan->channumber
		       && !doneearly && scanned < 2) {

			lbs_deb_scan("channel %d, radio %d, passive %d, "
				"dischanflt %d, maxscantime %d\n",
				ptmpchan->channumber,
				ptmpchan->radiotype,
			             ptmpchan->chanscanmode.passivescan,
			             ptmpchan->chanscanmode.disablechanfilt,
			             ptmpchan->maxscantime);

			/* Copy the current channel TLV to the command being prepared */
			memcpy(pchantlvout->chanscanparam + tlvidx,
			       ptmpchan, sizeof(pchantlvout->chanscanparam));

			/* Increment the TLV header length by the size appended */
			/* Ew, it would be _so_ nice if we could just declare the
			   variable little-endian and let GCC handle it for us */
			pchantlvout->header.len =
				cpu_to_le16(le16_to_cpu(pchantlvout->header.len) +
					    sizeof(pchantlvout->chanscanparam));

			/*
			 *  The tlv buffer length is set to the number of bytes of the
			 *    between the channel tlv pointer and the start of the
			 *    tlv buffer.  This compensates for any TLVs that were appended
			 *    before the channel list.
			 */
			pscancfgout->tlvbufferlen = ((u8 *) pchantlvout
						     - pscancfgout->tlvbuffer);

			/*  Add the size of the channel tlv header and the data length */
			pscancfgout->tlvbufferlen +=
			    (sizeof(pchantlvout->header)
			     + le16_to_cpu(pchantlvout->header.len));

			/* Increment the index to the channel tlv we are constructing */
			tlvidx++;

			doneearly = 0;

			/* Stop the loop if the *current* channel is in the 1,6,11 set
			 *   and we are not filtering on a BSSID or SSID.
			 */
			if (!filteredscan && (ptmpchan->channumber == 1
					      || ptmpchan->channumber == 6
					      || ptmpchan->channumber == 11)) {
				doneearly = 1;
			}

			/* Increment the tmp pointer to the next channel to be scanned */
			ptmpchan++;
			scanned++;

			/* Stop the loop if the *next* channel is in the 1,6,11 set.
			 *  This will cause it to be the only channel scanned on the next
			 *  interation
			 */
			if (!filteredscan && (ptmpchan->channumber == 1
					      || ptmpchan->channumber == 6
					      || ptmpchan->channumber == 11)) {
				doneearly = 1;
			}
		}

		/* Send the scan command to the firmware with the specified cfg */
		ret = libertas_prepare_and_send_command(priv, CMD_802_11_SCAN, 0,
					    0, 0, pscancfgout);
		if (scanned >= 2 && !full_scan) {
			ret = 0;
			goto done;
		}
		scanned = 0;
	}

done:
	priv->adapter->last_scanned_channel = ptmpchan->channumber;

	if (priv->adapter->last_scanned_channel) {
		/* Schedule the next part of the partial scan */
		if (!full_scan && !priv->adapter->surpriseremoved) {
			cancel_delayed_work(&priv->scan_work);
			queue_delayed_work(priv->work_thread, &priv->scan_work,
			                   msecs_to_jiffies(300));
		}
	} else {
		/* All done, tell userspace the scan table has been updated */
		memset(&wrqu, 0, sizeof(union iwreq_data));
		wireless_send_event(priv->dev, SIOCGIWSCAN, &wrqu, NULL);
	}

out:
	lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
	return ret;
}

/*
 * Only used from wlan_scan_networks()
*/
static void clear_selected_scan_list_entries(wlan_adapter *adapter,
	const struct wlan_ioctl_user_scan_cfg *scan_cfg)
{
	struct bss_descriptor *bss;
	struct bss_descriptor *safe;
	u32 clear_ssid_flag = 0, clear_bssid_flag = 0;

	lbs_deb_enter(LBS_DEB_SCAN);

	if (!scan_cfg)
		goto out;

	if (scan_cfg->clear_ssid && scan_cfg->ssid_len)
		clear_ssid_flag = 1;

	if (scan_cfg->clear_bssid
	    && (compare_ether_addr(scan_cfg->bssid, &zeromac[0]) != 0)
	    && (compare_ether_addr(scan_cfg->bssid, &bcastmac[0]) != 0)) {
		clear_bssid_flag = 1;
	}

	if (!clear_ssid_flag && !clear_bssid_flag)
		goto out;

	mutex_lock(&adapter->lock);
	list_for_each_entry_safe (bss, safe, &adapter->network_list, list) {
		u32 clear = 0;

		/* Check for an SSID match */
		if (   clear_ssid_flag
		    && (bss->ssid_len == scan_cfg->ssid_len)
		    && !memcmp(bss->ssid, scan_cfg->ssid, bss->ssid_len))
			clear = 1;

		/* Check for a BSSID match */
		if (   clear_bssid_flag
		    && !compare_ether_addr(bss->bssid, scan_cfg->bssid))
			clear = 1;

		if (clear) {
			list_move_tail (&bss->list, &adapter->network_free_list);
			clear_bss_descriptor(bss);
		}
	}
	mutex_unlock(&adapter->lock);
out:
	lbs_deb_leave(LBS_DEB_SCAN);
}


/**
 *  @brief Internal function used to start a scan based on an input config
 *
 *  Also used from debugfs
 *
 *  Use the input user scan configuration information when provided in
 *    order to send the appropriate scan commands to firmware to populate or
 *    update the internal driver scan table
 *
 *  @param priv          A pointer to wlan_private structure
 *  @param puserscanin   Pointer to the input configuration for the requested
 *                       scan.
 *  @param full_scan     ???
 *
 *  @return              0 or < 0 if error
 */
int wlan_scan_networks(wlan_private * priv,
                       const struct wlan_ioctl_user_scan_cfg * puserscanin,
                       int full_scan)
{
	wlan_adapter * adapter = priv->adapter;
	struct mrvlietypes_chanlistparamset *pchantlvout;
	struct chanscanparamset * scan_chan_list = NULL;
	struct wlan_scan_cmd_config * scan_cfg = NULL;
	u8 filteredscan;
	u8 scancurrentchanonly;
	int maxchanperscan;
	int ret;
#ifdef CONFIG_LIBERTAS_DEBUG
	struct bss_descriptor * iter_bss;
	int i = 0;
	DECLARE_MAC_BUF(mac);
#endif

	lbs_deb_enter_args(LBS_DEB_SCAN, "full_scan %d", full_scan);

	/* Cancel any partial outstanding partial scans if this scan
	 * is a full scan.
	 */
	if (full_scan && delayed_work_pending(&priv->scan_work))
		cancel_delayed_work(&priv->scan_work);

	scan_chan_list = kzalloc(sizeof(struct chanscanparamset) *
				WLAN_IOCTL_USER_SCAN_CHAN_MAX, GFP_KERNEL);
	if (scan_chan_list == NULL) {
		ret = -ENOMEM;
		goto out;
	}

	scan_cfg = wlan_scan_setup_scan_config(priv,
					       puserscanin,
					       &pchantlvout,
					       scan_chan_list,
					       &maxchanperscan,
					       &filteredscan,
					       &scancurrentchanonly);
	if (scan_cfg == NULL) {
		ret = -ENOMEM;
		goto out;
	}

	clear_selected_scan_list_entries(adapter, puserscanin);

	/* Keep the data path active if we are only scanning our current channel */
	if (!scancurrentchanonly) {
		netif_stop_queue(priv->dev);
		netif_carrier_off(priv->dev);
		if (priv->mesh_dev) {
			netif_stop_queue(priv->mesh_dev);
			netif_carrier_off(priv->mesh_dev);
		}
	}

	ret = wlan_scan_channel_list(priv,
				     maxchanperscan,
				     filteredscan,
				     scan_cfg,
				     pchantlvout,
				     scan_chan_list,
				     puserscanin,
				     full_scan);

#ifdef CONFIG_LIBERTAS_DEBUG
	/* Dump the scan table */
	mutex_lock(&adapter->lock);
	lbs_deb_scan("The scan table contains:\n");
	list_for_each_entry (iter_bss, &adapter->network_list, list) {
		lbs_deb_scan("scan %02d, %s, RSSI, %d, SSID '%s'\n",
		       i++, print_mac(mac, iter_bss->bssid), (s32) iter_bss->rssi,
		       escape_essid(iter_bss->ssid, iter_bss->ssid_len));
	}
	mutex_unlock(&adapter->lock);
#endif

	if (priv->adapter->connect_status == LIBERTAS_CONNECTED) {
		netif_carrier_on(priv->dev);
		netif_wake_queue(priv->dev);
		if (priv->mesh_dev) {
			netif_carrier_on(priv->mesh_dev);
			netif_wake_queue(priv->mesh_dev);
		}
	}

out:
	if (scan_cfg)
		kfree(scan_cfg);

	if (scan_chan_list)
		kfree(scan_chan_list);

	lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
	return ret;
}

/**
 *  @brief Interpret a BSS scan response returned from the firmware
 *
 *  Parse the various fixed fields and IEs passed back for a a BSS probe
 *   response or beacon from the scan command.  Record information as needed
 *   in the scan table struct bss_descriptor for that entry.
 *
 *  @param bss  Output parameter: Pointer to the BSS Entry
 *
 *  @return             0 or -1
 */
static int libertas_process_bss(struct bss_descriptor * bss,
				u8 ** pbeaconinfo, int *bytesleft)
{
	struct ieeetypes_fhparamset *pFH;
	struct ieeetypes_dsparamset *pDS;
	struct ieeetypes_cfparamset *pCF;