path: root/drivers/net/wireless/libertas/scan.c

/**
  * 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/etherdevice.h>
#include <asm/unaligned.h>

#include "host.h"
#include "decl.h"
#include "dev.h"
#include "scan.h"
#include "cmd.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 cmd_ds_802_11_scan with all TLVs at max
#define MAX_SCAN_CFG_ALLOC (sizeof(struct cmd_ds_802_11_scan)	\
                            + 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 int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy,
			      struct cmd_header *resp);

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

/**
 *  @brief Unsets the MSB on basic rates
 *
 * Scan through an array and unset the MSB for basic data rates.
 *
 *  @param rates     buffer of data rates
 *  @param len       size of buffer
 */
static void lbs_unset_basic_rate_flags(u8 *rates, size_t len)
{
	int i;

	for (i = 0; i < len; i++)
		rates[i] &= 0x7f;
}


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));
}

/**
 *  @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 lbs_ssid_cmp(uint8_t *ssid1, uint8_t ssid1_len, uint8_t *ssid2,
		 uint8_t ssid2_len)
{
	if (ssid1_len != ssid2_len)
		return -1;

	return memcmp(ssid1, ssid2, ssid1_len);
}

static inline int is_same_network(struct bss_descriptor *src,
				  struct bss_descriptor *dst)
{
	/* A network is only a duplicate if the channel, BSSID, and ESSID
	 * all match.  We treat all <hidden> with the same BSSID and channel
	 * as one network */
	return ((src->ssid_len == dst->ssid_len) &&
		(src->channel == dst->channel) &&
		!compare_ether_addr(src->bssid, dst->bssid) &&
		!memcmp(src->ssid, dst->ssid, src->ssid_len));
}




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

/**
 *  @brief Create a channel list for the driver to scan based on region info
 *
 *  Only used from lbs_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 struct lbs_private structure
 *  @param scanchanlist  Output parameter: resulting channel list to scan
 *
 *  @return              void
 */
static int lbs_scan_create_channel_list(struct lbs_private *priv,
					struct chanscanparamset *scanchanlist)
{
	struct region_channel *scanregion;
	struct chan_freq_power *cfp;
	int rgnidx;
	int chanidx;
	int nextchan;
	uint8_t scantype;

	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)
	 */