scan.c

linux内核源码

/**
  * Functions implementing wlan scan IOCTL and firmware command APIs
  *
  * IOCTL handlers as well as command preperation and response routines
  *  for sending scan commands to the firmware.
  */
#include <linux/ctype.h>
#include <linux/if.h>
#include <linux/netdevice.h>
#include <linux/wireless.h>
#include <linux/etherdevice.h>

#include <net/ieee80211.h>
#include <net/iw_handler.h>

#include <asm/unaligned.h>

#include "host.h"
#include "decl.h"
#include "dev.h"
#include "scan.h"
#include "join.h"

//! Approximate amount of data needed to pass a scan result back to iwlist
#define MAX_SCAN_CELL_SIZE  (IW_EV_ADDR_LEN             \
                             + IW_ESSID_MAX_SIZE        \
                             + IW_EV_UINT_LEN           \
                             + IW_EV_FREQ_LEN           \
                             + IW_EV_QUAL_LEN           \
                             + IW_ESSID_MAX_SIZE        \
                             + IW_EV_PARAM_LEN          \
                             + 40)	/* 40 for WPAIE */

//! Memory needed to store a max sized channel List TLV for a firmware scan
#define CHAN_TLV_MAX_SIZE  (sizeof(struct mrvlietypesheader)    \
                            + (MRVDRV_MAX_CHANNELS_PER_SCAN     \
                               * sizeof(struct chanscanparamset)))

//! Memory needed to store a max number/size SSID TLV for a firmware scan
#define SSID_TLV_MAX_SIZE  (1 * sizeof(struct mrvlietypes_ssidparamset))

//! Maximum memory needed for a wlan_scan_cmd_config with all TLVs at max
#define MAX_SCAN_CFG_ALLOC (sizeof(struct wlan_scan_cmd_config)  \
                            + sizeof(struct mrvlietypes_numprobes)   \
                            + CHAN_TLV_MAX_SIZE                 \
                            + SSID_TLV_MAX_SIZE)

//! The maximum number of channels the firmware can scan per command
#define MRVDRV_MAX_CHANNELS_PER_SCAN   14

/**
 * @brief Number of channels to scan per firmware scan command issuance.
 *
 *  Number restricted to prevent hitting the limit on the amount of scan data
 *  returned in a single firmware scan command.
 */
#define MRVDRV_CHANNELS_PER_SCAN_CMD   4

//! Scan time specified in the channel TLV for each channel for passive scans
#define MRVDRV_PASSIVE_SCAN_CHAN_TIME  100

//! Scan time specified in the channel TLV for each channel for active scans
#define MRVDRV_ACTIVE_SCAN_CHAN_TIME   100

static const u8 zeromac[ETH_ALEN] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
static const u8 bcastmac[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };




/*********************************************************************/
/*                                                                   */
/*  Misc helper functions                                            */
/*                                                                   */
/*********************************************************************/

static inline void clear_bss_descriptor (struct bss_descriptor * bss)
{
	/* Don't blow away ->list, just BSS data */
	memset(bss, 0, offsetof(struct bss_descriptor, list));
}

static inline int match_bss_no_security(struct wlan_802_11_security * secinfo,
			struct bss_descriptor * match_bss)
{
	if (   !secinfo->wep_enabled
	    && !secinfo->WPAenabled
	    && !secinfo->WPA2enabled
	    && match_bss->wpa_ie[0] != MFIE_TYPE_GENERIC
	    && match_bss->rsn_ie[0] != MFIE_TYPE_RSN
	    && !(match_bss->capability & WLAN_CAPABILITY_PRIVACY)) {
		return 1;
	}
	return 0;
}

static inline int match_bss_static_wep(struct wlan_802_11_security * secinfo,
			struct bss_descriptor * match_bss)
{
	if ( secinfo->wep_enabled
	   && !secinfo->WPAenabled
	   && !secinfo->WPA2enabled
	   && (match_bss->capability & WLAN_CAPABILITY_PRIVACY)) {
		return 1;
	}
	return 0;
}

static inline int match_bss_wpa(struct wlan_802_11_security * secinfo,
			struct bss_descriptor * match_bss)
{
	if (  !secinfo->wep_enabled
	   && secinfo->WPAenabled
	   && (match_bss->wpa_ie[0] == MFIE_TYPE_GENERIC)
	   /* privacy bit may NOT be set in some APs like LinkSys WRT54G
	      && (match_bss->capability & WLAN_CAPABILITY_PRIVACY)) {
	    */
	   ) {
		return 1;
	}
	return 0;
}

static inline int match_bss_wpa2(struct wlan_802_11_security * secinfo,
			struct bss_descriptor * match_bss)
{
	if (  !secinfo->wep_enabled
	   && secinfo->WPA2enabled
	   && (match_bss->rsn_ie[0] == MFIE_TYPE_RSN)
	   /* privacy bit may NOT be set in some APs like LinkSys WRT54G
	      && (match_bss->capability & WLAN_CAPABILITY_PRIVACY)) {
	    */
	   ) {
		return 1;
	}
	return 0;
}

static inline int match_bss_dynamic_wep(struct wlan_802_11_security * secinfo,
			struct bss_descriptor * match_bss)
{
	if (  !secinfo->wep_enabled
	   && !secinfo->WPAenabled
	   && !secinfo->WPA2enabled
	   && (match_bss->wpa_ie[0] != MFIE_TYPE_GENERIC)
	   && (match_bss->rsn_ie[0] != MFIE_TYPE_RSN)
	   && (match_bss->capability & WLAN_CAPABILITY_PRIVACY)) {
		return 1;
	}
	return 0;
}

/**
 *  @brief Check if a scanned network compatible with the driver settings
 *
 *   WEP     WPA     WPA2    ad-hoc  encrypt                      Network
 * enabled enabled  enabled   AES     mode   privacy  WPA  WPA2  Compatible
 *    0       0        0       0      NONE      0      0    0   yes No security
 *    1       0        0       0      NONE      1      0    0   yes Static WEP
 *    0       1        0       0       x        1x     1    x   yes WPA
 *    0       0        1       0       x        1x     x    1   yes WPA2
 *    0       0        0       1      NONE      1      0    0   yes Ad-hoc AES
 *    0       0        0       0     !=NONE     1      0    0   yes Dynamic WEP
 *
 *
 *  @param adapter A pointer to wlan_adapter
 *  @param index   Index in scantable to check against current driver settings
 *  @param mode    Network mode: Infrastructure or IBSS
 *
 *  @return        Index in scantable, or error code if negative
 */
static int is_network_compatible(wlan_adapter * adapter,
		struct bss_descriptor * bss, u8 mode)
{
	int matched = 0;

	lbs_deb_enter(LBS_DEB_SCAN);

	if (bss->mode != mode)
		goto done;

	if ((matched = match_bss_no_security(&adapter->secinfo, bss))) {
		goto done;
	} else if ((matched = match_bss_static_wep(&adapter->secinfo, bss))) {
		goto done;
	} else if ((matched = match_bss_wpa(&adapter->secinfo, bss))) {
		lbs_deb_scan(
		       "is_network_compatible() WPA: wpa_ie=%#x "
		       "wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s "
		       "privacy=%#x\n", bss->wpa_ie[0], bss->rsn_ie[0],
		       adapter->secinfo.wep_enabled ? "e" : "d",
		       adapter->secinfo.WPAenabled ? "e" : "d",
		       adapter->secinfo.WPA2enabled ? "e" : "d",
		       (bss->capability & WLAN_CAPABILITY_PRIVACY));
		goto done;
	} else if ((matched = match_bss_wpa2(&adapter->secinfo, bss))) {
		lbs_deb_scan(
		       "is_network_compatible() WPA2: wpa_ie=%#x "
		       "wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s "
		       "privacy=%#x\n", bss->wpa_ie[0], bss->rsn_ie[0],
		       adapter->secinfo.wep_enabled ? "e" : "d",
		       adapter->secinfo.WPAenabled ? "e" : "d",
		       adapter->secinfo.WPA2enabled ? "e" : "d",
		       (bss->capability & WLAN_CAPABILITY_PRIVACY));
		goto done;
	} else if ((matched = match_bss_dynamic_wep(&adapter->secinfo, bss))) {
		lbs_deb_scan(
		       "is_network_compatible() dynamic WEP: "
		       "wpa_ie=%#x wpa2_ie=%#x privacy=%#x\n",
		       bss->wpa_ie[0], bss->rsn_ie[0],
		       (bss->capability & WLAN_CAPABILITY_PRIVACY));
		goto done;
	}

	/* bss security settings don't match those configured on card */
	lbs_deb_scan(
	       "is_network_compatible() FAILED: wpa_ie=%#x "
	       "wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s privacy=%#x\n",
	       bss->wpa_ie[0], bss->rsn_ie[0],
	       adapter->secinfo.wep_enabled ? "e" : "d",
	       adapter->secinfo.WPAenabled ? "e" : "d",
	       adapter->secinfo.WPA2enabled ? "e" : "d",
	       (bss->capability & WLAN_CAPABILITY_PRIVACY));

done:
	lbs_deb_leave_args(LBS_DEB_SCAN, "matched: %d", matched);
	return matched;
}

/**
 *  @brief Compare two SSIDs
 *
 *  @param ssid1    A pointer to ssid to compare
 *  @param ssid2    A pointer to ssid to compare
 *
 *  @return         0--ssid is same, otherwise is different
 */
int libertas_ssid_cmp(u8 *ssid1, u8 ssid1_len, u8 *ssid2, u8 ssid2_len)
{
	if (ssid1_len != ssid2_len)
		return -1;

	return memcmp(ssid1, ssid2, ssid1_len);
}




/*********************************************************************/
/*                                                                   */
/*  Main scanning support                                            */
/*                                                                   */
/*********************************************************************/


/**
 *  @brief Create a channel list for the driver to scan based on region info
 *
 *  Only used from wlan_scan_setup_scan_config()
 *
 *  Use the driver region/band information to construct a comprehensive list
 *    of channels to scan.  This routine is used for any scan that is not
 *    provided a specific channel list to scan.
 *
 *  @param priv          A pointer to wlan_private structure
 *  @param scanchanlist  Output parameter: resulting channel list to scan
 *  @param filteredscan  Flag indicating whether or not a BSSID or SSID filter
 *                       is being sent in the command to firmware.  Used to
 *                       increase the number of channels sent in a scan
 *                       command and to disable the firmware channel scan
 *                       filter.
 *
 *  @return              void
 */
static void wlan_scan_create_channel_list(wlan_private * priv,
					  struct chanscanparamset * scanchanlist,
					  u8 filteredscan)
{

	wlan_adapter *adapter = priv->adapter;
	struct region_channel *scanregion;
	struct chan_freq_power *cfp;
	int rgnidx;
	int chanidx;
	int nextchan;
	u8 scantype;

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

	chanidx = 0;

	/* Set the default scan type to the user specified type, will later
	 *   be changed to passive on a per channel basis if restricted by
	 *   regulatory requirements (11d or 11h)
	 */
	scantype = CMD_SCAN_TYPE_ACTIVE;

	for (rgnidx = 0; rgnidx < ARRAY_SIZE(adapter->region_channel); rgnidx++) {
		if (priv->adapter->enable11d &&
		    adapter->connect_status != LIBERTAS_CONNECTED) {
			/* Scan all the supported chan for the first scan */
			if (!adapter->universal_channel[rgnidx].valid)
				continue;
			scanregion = &adapter->universal_channel[rgnidx];

			/* clear the parsed_region_chan for the first scan */
			memset(&adapter->parsed_region_chan, 0x00,
			       sizeof(adapter->parsed_region_chan));
		} else {
			if (!adapter->region_channel[rgnidx].valid)
				continue;
			scanregion = &adapter->region_channel[rgnidx];
		}

		for (nextchan = 0;
		     nextchan < scanregion->nrcfp; nextchan++, chanidx++) {

			cfp = scanregion->CFP + nextchan;

			if (priv->adapter->enable11d) {
				scantype =
				    libertas_get_scan_type_11d(cfp->channel,
							   &adapter->
							   parsed_region_chan);
			}

			switch (scanregion->band) {
			case BAND_B:
			case BAND_G:
			default:
				scanchanlist[chanidx].radiotype =
				    CMD_SCAN_RADIO_TYPE_BG;
				break;
			}

			if (scantype == CMD_SCAN_TYPE_PASSIVE) {
				scanchanlist[chanidx].maxscantime =
				    cpu_to_le16(MRVDRV_PASSIVE_SCAN_CHAN_TIME);
				scanchanlist[chanidx].chanscanmode.passivescan =
				    1;
			} else {
				scanchanlist[chanidx].maxscantime =
				    cpu_to_le16(MRVDRV_ACTIVE_SCAN_CHAN_TIME);
				scanchanlist[chanidx].chanscanmode.passivescan =
				    0;
			}

			scanchanlist[chanidx].channumber = cfp->channel;

			if (filteredscan) {
				scanchanlist[chanidx].chanscanmode.
				    disablechanfilt = 1;
			}
		}
	}
}


/* Delayed partial scan worker */
void libertas_scan_worker(struct work_struct *work)
{
	wlan_private *priv = container_of(work, wlan_private, scan_work.work);

	wlan_scan_networks(priv, NULL, 0);
}


/**
 *  @brief Construct a wlan_scan_cmd_config structure to use in issue scan cmds
 *
 *  Application layer or other functions can invoke wlan_scan_networks
 *    with a scan configuration supplied in a wlan_ioctl_user_scan_cfg struct.
 *    This structure is used as the basis of one or many wlan_scan_cmd_config
 *    commands that are sent to the command processing module and sent to
 *    firmware.
 *
 *  Create a wlan_scan_cmd_config based on the following user supplied
 *    parameters (if present):
 *             - SSID filter
 *             - BSSID filter
 *             - Number of Probes to be sent
 *             - channel list
 *
 *  If the SSID or BSSID filter is not present, disable/clear the filter.
 *  If the number of probes is not set, use the adapter default setting
 *  Qualify the channel
 *
 *  @param priv             A pointer to wlan_private structure
 *  @param puserscanin      NULL or pointer to scan configuration parameters
 *  @param ppchantlvout     Output parameter: Pointer to the start of the
 *                          channel TLV portion of the output scan config
 *  @param pscanchanlist    Output parameter: Pointer to the resulting channel
 *                          list to scan
 *  @param pmaxchanperscan  Output parameter: Number of channels to scan for
 *                          each issuance of the firmware scan command
 *  @param pfilteredscan    Output parameter: Flag indicating whether or not
 *                          a BSSID or SSID filter is being sent in the
 *                          command to firmware.  Used to increase the number
 *                          of channels sent in a scan command and to
 *                          disable the firmware channel scan filter.
 *  @param pscancurrentonly Output parameter: Flag indicating whether or not
 *                          we are only scanning our current active channel
 *
 *  @return                 resulting scan configuration
 */
static struct wlan_scan_cmd_config *
wlan_scan_setup_scan_config(wlan_private * priv,
			    const struct wlan_ioctl_user_scan_cfg * puserscanin,
			    struct mrvlietypes_chanlistparamset ** ppchantlvout,
			    struct chanscanparamset * pscanchanlist,
			    int *pmaxchanperscan,
			    u8 * pfilteredscan,
			    u8 * pscancurrentonly)
{
	struct mrvlietypes_numprobes *pnumprobestlv;
	struct mrvlietypes_ssidparamset *pssidtlv;
	struct wlan_scan_cmd_config * pscancfgout = NULL;
	u8 *ptlvpos;
	u16 numprobes;
	int chanidx;
	int scantype;
	int scandur;
	int channel;
	int radiotype;

	lbs_deb_enter(LBS_DEB_SCAN);

	pscancfgout = kzalloc(MAX_SCAN_CFG_ALLOC, GFP_KERNEL);
	if (pscancfgout == NULL)
		goto out;

	/* The tlvbufferlen is calculated for each scan command.  The TLVs added
	 *   in this routine will be preserved since the routine that sends
	 *   the command will append channelTLVs at *ppchantlvout.  The difference
	 *   between the *ppchantlvout and the tlvbuffer start will be used
	 *   to calculate the size of anything we add in this routine.
	 */
	pscancfgout->tlvbufferlen = 0;

	/* Running tlv pointer.  Assigned to ppchantlvout at end of function
	 *  so later routines know where channels can be added to the command buf
	 */
	ptlvpos = pscancfgout->tlvbuffer;

	/*
	 * Set the initial scan paramters for progressive scanning.  If a specific
	 *   BSSID or SSID is used, the number of channels in the scan command
	 *   will be increased to the absolute maximum
	 */
	*pmaxchanperscan = MRVDRV_CHANNELS_PER_SCAN_CMD;

	/* Initialize the scan as un-filtered by firmware, set to TRUE below if
	 *   a SSID or BSSID filter is sent in the command
	 */
	*pfilteredscan = 0;

	/* Initialize the scan as not being only on the current channel.  If
	 *   the channel list is customized, only contains one channel, and
	 *   is the active channel, this is set true and data flow is not halted.
	 */
	*pscancurrentonly = 0;

	if (puserscanin) {
		/* Set the bss type scan filter, use adapter setting if unset */
		pscancfgout->bsstype =
		    puserscanin->bsstype ? puserscanin->bsstype : CMD_BSS_TYPE_ANY;

		/* Set the number of probes to send, use adapter setting if unset */