PPC 에서 무선랜 핸들링 참고문서 :: 전산쟁이의 카피질

PDA 같은 경우에는 DeviceIoControl로 OID_802_11_BSSID_LIST를 쿼리를 하면 주변 ap BeaconPeriod, Rssi, Mac , SSID 같은 값을 찾을 수 있음

http://www.devpia.com/MAEUL/Contents/Detail.aspx?BoardID=59&MAEULNo=23&no=20416&ref=20416

참조 키워드 : WinceWifi

참조 중국 사이트 : http://www.pudn.com/downloads74/sourcecode/embed/detail266030.html

http://read.pudn.com/downloads74/sourcecode/embed/266030/WifiDemo/Wifi.cpp__.htm

</div><div><div>// accesspoints.cpp : Defines the entry point for the console application.</div><div>//</div><div>#include "stdafx.h"</div><div>#include <windows.h></div><div>#include <commctrl.h></div><div>#include <stdlib.h></div><div>#include <ntddndis.h></div><div>#include <nuiouser.h></div><div>#include <winioctl.h></div><div>#include "strconv.h"</div><div>
</div><div>int _tmain(int argc, _TCHAR* argv[])</div><div>{</div><div>    if (argc < 2)</div><div>    {</div><div>        printf("Usage: accesspoints <adapter name> [delay in ms]\n");</div><div>        printf("       <adapter name> name of the wireless adapter\n");</div><div>        printf("       [delay in ms]  delay between scan and list query\n");</div><div>        return -1;</div><div>    }</div><div>
</div><div>    LPCTSTR pszAdapter = argv[1];</div><div>
</div><div>    HANDLE hDevice = CreateFile(</div><div>        NDISUIO_DEVICE_NAME, GENERIC_READ, </div><div>        FILE_SHARE_READ | FILE_SHARE_WRITE, </div><div>        NULL, OPEN_EXISTING, </div><div>        FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,</div><div>        NULL);</div><div>
</div><div>    if (hDevice == INVALID_HANDLE_VALUE)</div><div>    {</div><div>        DWORD dwError = GetLastError();</div><div>
</div><div>        printf("Function \"CreateFile\" failed (0x%08x).\n", dwError);</div><div>        return -2;</div><div>    }</div><div>
</div><div>    DWORD dwBytesReturned = 0;</div><div>
</div><div>    NDISUIO_QUERY_OID NDISUIOQueryOid = {0};</div><div>    NDISUIOQueryOid.ptcDeviceName = (PTCHAR) pszAdapter;</div><div>    NDISUIOQueryOid.Oid = OID_GEN_PHYSICAL_MEDIUM;</div><div>
</div><div>    if (!DeviceIoControl(</div><div>        hDevice, IOCTL_NDISUIO_QUERY_OID_VALUE,</div><div>        &NDISUIOQueryOid, sizeof(NDISUIOQueryOid),</div><div>        &NDISUIOQueryOid, sizeof(NDISUIOQueryOid),</div><div>        &dwBytesReturned, NULL))</div><div>    {</div><div>        DWORD dwError = GetLastError();</div><div>
</div><div>        CloseHandle(hDevice);</div><div>        printf("Function \"DeviceIoControl\" (OID_GEN_PHYSICAL_MEDIUM) failed (0x%08x).\n", </div><div>            dwError);</div><div>        return -3;</div><div>    }</div><div>
</div><div>    if (*((PNDIS_PHYSICAL_MEDIUM) NDISUIOQueryOid.Data) != NdisPhysicalMediumWirelessLan)</div><div>    {</div><div>        CloseHandle(hDevice);</div><div>        printf("Device \"%s\" is no wireless adapter.\n", CTtoA(pszAdapter));</div><div>        return -4;</div><div>    }</div><div>
</div><div>    CTtoW deviceName(pszAdapter);</div><div>
</div><div><span class="Apple-tab-span" style="white-space:pre">	</span>if (!DeviceIoControl(</div><div>        hDevice, IOCTL_NDISUIO_OPEN_DEVICE,</div><div>        (LPVOID)(LPCWSTR) deviceName,</div><div>        deviceName.GetLength() * sizeof(WCHAR),</div><div>        NULL, 0, &dwBytesReturned, NULL))</div><div>    {</div><div>        DWORD dwError = GetLastError();</div><div>
</div><div>        CloseHandle(hDevice);</div><div>        printf("Function \"DeviceIoControl\" (IOCTL_NDISUIO_OPEN_DEVICE) failed (0x%08x).\n", </div><div>            dwError);</div><div>        return -5;</div><div>    }</div><div>
</div><div>    NDISUIO_SET_OID NDISUIOSetOid = {0};  </div><div>    NDISUIOSetOid.ptcDeviceName = (PTCHAR) pszAdapter;  </div><div>    NDISUIOSetOid.Oid = OID_802_11_BSSID_LIST_SCAN;  </div><div>
</div><div>    if (!DeviceIoControl(  </div><div>        hDevice, IOCTL_NDISUIO_SET_OID_VALUE,   </div><div>        &NDISUIOSetOid, sizeof(NDISUIOSetOid),   </div><div>        NULL, 0,   </div><div>        &dwBytesReturned, NULL))  </div><div>    {  </div><div>        DWORD dwError = GetLastError();  </div><div>  </div><div>        CloseHandle(hDevice);  </div><div>        printf("Function \"DeviceIoControl\" (OID_802_11_BSSID_LIST_SCAN) failed (0x%08x).\n",   </div><div>            dwError);  </div><div>        return -6;  </div><div>    }  </div><div>
</div><div>    if (argc >= 3)</div><div>    {</div><div>        Sleep((DWORD)_ttoi(argv[2]));</div><div>    }</div><div>
</div><div>    for (int i = 1;; ++i)</div><div>    {</div><div>        const DWORD queryMemSize = sizeof(NDISUIO_QUERY_OID) + sizeof(NDIS_WLAN_BSSID_EX) * i;</div><div>        PNDISUIO_QUERY_OID pNDISUIOQueryOid = (PNDISUIO_QUERY_OID) malloc(queryMemSize);</div><div>
</div><div>        pNDISUIOQueryOid->ptcDeviceName = (PTCHAR) pszAdapter;</div><div>        pNDISUIOQueryOid->Oid = OID_802_11_BSSID_LIST;</div><div>
</div><div>        if (!DeviceIoControl(</div><div>            hDevice, IOCTL_NDISUIO_QUERY_OID_VALUE, </div><div>            pNDISUIOQueryOid, queryMemSize, </div><div>            pNDISUIOQueryOid, queryMemSize, </div><div>            &dwBytesReturned, NULL))</div><div>        {</div><div>            DWORD dwError = GetLastError();</div><div>
</div><div>            free(pNDISUIOQueryOid);</div><div>
</div><div>            if (dwError == ERROR_INVALID_USER_BUFFER ||</div><div>                dwError == ERROR_INSUFFICIENT_BUFFER)</div><div>                continue;</div><div>
</div><div>            CloseHandle(hDevice);</div><div>            printf("Function \"DeviceIoControl\" (OID_802_11_BSSID_LIST) failed (0x%08x).\n", </div><div>                dwError);</div><div>            return -7;</div><div>        }</div><div>
</div><div>        PNDIS_802_11_BSSID_LIST_EX pBssidList = (PNDIS_802_11_BSSID_LIST_EX) pNDISUIOQueryOid->Data;</div><div>
</div><div>        const int accessPointsCnt = (int) pBssidList->NumberOfItems;</div><div>
</div><div>        printf("Found %d access point(s).\n", accessPointsCnt);</div><div>
</div><div>        PNDIS_WLAN_BSSID_EX pBssid = pBssidList->Bssid;</div><div>
</div><div>        for (int j = 0; j < accessPointsCnt; ++j)</div><div>        {</div><div>            printf("\n");</div><div>
</div><div>            printf("MacAddress        : %02X-%02X-%02X-%02X-%02X-%02X\n",</div><div>                pBssid->MacAddress[0], pBssid->MacAddress[1],</div><div>                pBssid->MacAddress[2], pBssid->MacAddress[3],</div><div>                pBssid->MacAddress[4], pBssid->MacAddress[5]);</div><div>
</div><div>            char* pSSID = (char*) malloc(pBssid->Ssid.SsidLength + 1);</div><div>            memcpy(pSSID, pBssid->Ssid.Ssid, pBssid->Ssid.SsidLength);</div><div>            pSSID[pBssid->Ssid.SsidLength] = '\0';</div><div>            printf("Ssid              : %s\n", pSSID);</div><div>            free(pSSID);</div><div>
</div><div>            printf("Privacy           : %s\n", pBssid->Privacy ? "Yes" : "No");</div><div>            printf("Rssi              : %ld dBm\n", pBssid->Rssi);</div><div>            printf("NetworkTypeInUse  : %s\n", </div><div>                pBssid->NetworkTypeInUse == Ndis802_11FH ? "Ndis802_11FH" : </div><div>                pBssid->NetworkTypeInUse == Ndis802_11DS ? "Ndis802_11DS" :</div><div>                "<unknown>");</div><div>            printf("BeaconPeriod      : %lu Kusec\n", pBssid->Configuration.BeaconPeriod);</div><div>            printf("ATIMWindow        : %lu Kusec\n", pBssid->Configuration.ATIMWindow);</div><div>
</div><div>            if (pBssid->NetworkTypeInUse == Ndis802_11DS)</div><div>            {</div><div>                printf("DSConfig          : %lu kHz\n", pBssid->Configuration.DSConfig);</div><div>            }</div><div>            else if (pBssid->NetworkTypeInUse == Ndis802_11FH)</div><div>            {</div><div>                printf("HopPattern        : %lu\n", pBssid->Configuration.FHConfig.HopPattern);</div><div>                printf("HopSet            : %lu\n", pBssid->Configuration.FHConfig.HopSet);</div><div>                printf("DwellTime         : %lu Kusec\n", pBssid->Configuration.FHConfig.DwellTime);</div><div>            }</div><div>
</div><div>            printf("InfrastructureMode: %s\n",</div><div>                pBssid->InfrastructureMode == Ndis802_11IBSS ? "Ndis802_11IBSS" :</div><div>                pBssid->InfrastructureMode == Ndis802_11Infrastructure ? "Ndis802_11Infrastructure" :</div><div>                pBssid->InfrastructureMode == Ndis802_11AutoUnknown ? "Ndis802_11AutoUnknown" :</div><div>                "<unknown>");</div><div>
</div><div>            printf("SupportedRates    : [0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x]\n",</div><div>                pBssid->SupportedRates[0], pBssid->SupportedRates[1], pBssid->SupportedRates[2], </div><div>                pBssid->SupportedRates[3], pBssid->SupportedRates[4], pBssid->SupportedRates[5], </div><div>                pBssid->SupportedRates[6], pBssid->SupportedRates[7]);   </div><div>
</div><div>            printf("                    BSSBasicRateSet (Mbps):");</div><div>            for (int n = 0; n < 8; ++n)</div><div>            {</div><div>                if (pBssid->SupportedRates[n] & 0x80)</div><div>                    printf(" %.1f", (pBssid->SupportedRates[n] & 0x7f) * 0.5f);</div><div>            }</div><div>            printf("\n");</div><div>
</div><div>            printf("                    Others (Mbps):");</div><div>            for (int n = 0; n < 8; ++n)</div><div>            {</div><div>                if (!(pBssid->SupportedRates[n] & 0x80))</div><div>                    printf(" %.1f", (pBssid->SupportedRates[n] & 0x7f) * 0.5f);</div><div>            }</div><div>            printf("\n");</div><div>
</div><div>            if (pBssid->Length >= sizeof(NDIS_802_11_BSSID_LIST_EX) && pBssid->IELength > 0)</div><div>            {</div><div>                printf("IEs               : [");</div><div>                for (ULONG n = 0; n < pBssid->IELength; ++n)</div><div>                {</div><div>                    printf("0x%02x", pBssid->IEs[n]);</div><div>                    if (n < pBssid->IELength - 1)</div><div>                        printf(", ");</div><div>                }</div><div>                printf("]\n");</div><div>            }</div><div>            </div><div>            pBssid = (PNDIS_WLAN_BSSID_EX) ((LPBYTE) pBssid + pBssid->Length);</div><div>        }</div><div>
</div><div>        free(pNDISUIOQueryOid);</div><div>
</div><div>        CloseHandle(hDevice);</div><div>
</div><div>        return accessPointsCnt;</div><div>    }</div><div>}</div><div>

코드 출처 : http://geekswithblogs.net/dastblog/archive/2006/11/30/100038.aspx

</div><div><pre>/*
 * Tux Droid - Wifi channel retrieving for windows.
 * Copyright (C) 2008 C2ME Sa
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <winsock2.h>

#define NUMBEROFSSIDS 10

/**
 * \name NDIS structures and defines.
 * @{
 */
/** Device type physical netcard */
#define FILE_DEVICE_PHYSICAL_NETCARD 23
/** File access type any */
#define FILE_ANY_ACCESS 0
/** File access method out direct */
#define METHOD_OUT_DIRECT 2
/**
 * This macro is used to create a unique system I/O control code (IOCTL).
 */
#define CTL_CODE(DeviceType, Function, Method, Access)( \
  ((DeviceType) << 16) | ((Access) << 14) | ((Function) << 2) | (Method))
/** NDIS IOCTL */
#define _NDIS_CONTROL_CODE(request, method) \
    CTL_CODE(FILE_DEVICE_PHYSICAL_NETCARD, request, method, FILE_ANY_ACCESS)
/** NDIS IOCTL Query global stats */
#define IOCTL_NDIS_QUERY_GLOBAL_STATS _NDIS_CONTROL_CODE(0, METHOD_OUT_DIRECT)
/** NDIS OID code for SSID */
#define OID_802_11_SSID 0x0D010102
/** NDIS OID code for BSSID list */
#define OID_802_11_BSSID_LIST 0x0D010217
/** NDIS OID code for BSSID list scan */
#define OID_802_11_BSSID_LIST_SCAN 0x0D01011A
/**
 * \brief This enumerated type holds the network subtype values for the
 *        physical layer of used with a specific driver.
 */
typedef enum _NDIS_802_11_NETWORK_TYPE
{
   Ndis802_11FH, /**< Indicates the physical layer of the frequency
                      hopping spread-spectrum radio. */
   Ndis802_11DS, /**< Indicates the physical layer of the direct
                      sequencing spread-spectrum radio. */
   Ndis802_11NetworkTypeMax /**< Specifies the upper bound. */
} NDIS_802_11_NETWORK_TYPE, *PNDIS_802_11_NETWORK_TYPE;
/**
 * \brief This data type is used to provide a received signal strength
 *        indication (RSSI).
 */
typedef LONG NDIS_802_11_RSSI;
/**
 * \brief specifies the frequency-hopping configuration for an
 *        NDIS_802_11_CONFIGURATION structure.
 * \param Length Specifies the length of the NDIS_802_11_CONFIGURATION_FH
 *               structure in bytes.
 * \param HopPattern Specifies the hop pattern used to determine the hop
 *                   sequence. As defined by the 802.11 standard, the layer
 *                   management entity (LME) of the physical layer uses a hop
 *                   pattern to determine the hop sequence.
 * \param HopSet Specifies a set of patterns. The LME of the physical layer
 *               uses these patterns to determine the hop sequence.
 * \param DwellTime Specifies the maximum period of time during which the
 *                  transmitter should remain fixed on a channel. This interval
 *                  is described in K탎ec (1024 탎ec).
 */
typedef struct _NDIS_802_11_CONFIGURATION_FH
{
   ULONG Length;
   ULONG HopPattern;
   ULONG HopSet;
   ULONG DwellTime;
} NDIS_802_11_CONFIGURATION_FH, *PNDIS_802_11_CONFIGURATION_FH;
/**
 * \brief Structure to describe the configuration of a radio.
 * \param Length Specifies the length of the NDIS_802_11_CONFIGURATION
 *               structure in bytes.
 * \param BeaconPeriod Specifies the interval between beacon message
 *                     transmissions. This value is specified in K탎ec
 *                     (1024 탎ec).
 * \param ATIMWindow Specifies the announcement traffic information message
 *                   (ATIM) window in K탎ec (1024 탎ec). The ATIM window is
 *                   a short time period immediately after the transmission
 *                   of each beacon in an IBSS configuration. During the ATIM
 *                   window, any station can indicate the need to transfer data
 *                   to another station during the following data-transmission
 *                   window.
 * \param DSConfig Specifies the frequency of the selected channel in kHz.
 * \param FHConfig Specifies the frequency-hopping configuration in an
 *                 NDIS_802_11_CONFIGURATION_FH structure.
 */
typedef struct _NDIS_802_11_CONFIGURATION
{
   ULONG Length;
   ULONG BeaconPeriod;
   ULONG ATIMWindow;
   ULONG DSConfig;
   NDIS_802_11_CONFIGURATION_FH    FHConfig;
} NDIS_802_11_CONFIGURATION, *PNDIS_802_11_CONFIGURATION;
/**
 * \brief This enumerated type holds specific infrastructure values for the
 *        miniport driver to set in an 802.11 NIC.
 */
typedef enum _NDIS_802_11_NETWORK_INFRASTRUCTURE
{
   Ndis802_11IBSS, /**< Specifies the independent basic service set (IBSS)
                        mode. This mode is also known as ad hoc mode. */
   Ndis802_11Infrastructure, /**< Specifies the infrastructure mode. */
   Ndis802_11AutoUnknown, /**< Specifies an automatic mode. In this mode,
                               the 802.11 NIC can switch between ad hoc and
                               infrastructure modes as required. */
   Ndis802_11InfrastructureMax /**< Specifies the upper bound. */
} NDIS_802_11_NETWORK_INFRASTRUCTURE, *PNDIS_802_11_NETWORK_INFRASTRUCTURE;
/**
 * \brief This enumerated type holds the 802.11 authentication mode value to
 *        invoke Open system or Shared Key authentication services.
 */
typedef enum _NDIS_802_11_AUTHENTICATION_MODE
{
   Ndis802_11AuthModeOpen, /**< Specifies 802.11 open authentication mode.
                                There are no checks when accepting clients
                                in this mode. */
   Ndis802_11AuthModeShared, /**< Specifies 802.11 shared authentication that
                                  uses a pre-shared wired equivalent privacy
                                  (WEP) key. */
   Ndis802_11AuthModeAutoSwitch, /**< Specifies auto-switch mode. When using
                                      auto-switch mode, the NIC tries 802.11
                                      shared authentication mode first. If
                                      shared mode fails, the NIC attempts to
                                      use 802.11 open authentication mode. */
   Ndis802_11AuthModeMax /**< Defines the upper bound. */
} NDIS_802_11_AUTHENTICATION_MODE, *PNDIS_802_11_AUTHENTICATION_MODE;
/**
 * \brief This data type provides a way to handle the data rates associated
 *        with 802.11 delivery.
 */
typedef UCHAR NDIS_802_11_RATES[8];
/**
 * \brief This data type holds the MAC address of the associated access point.
 *        The setting is useful when doing a site survey.
 */
typedef UCHAR NDIS_802_11_MAC_ADDRESS[6];
/**
 * \brief OID_802_11_SSID uses this structure when it requests a miniport
 *        driver to set or return the NIC service set identifier (SSID) value.
 * \param SsidLength Specifies the length of the Ssid member in octets.
 * \param Ssid Specifies the SSID. An empty string (that is, a string with the
 *             first byte set to zero) requests the 802.11 NIC to associate
 *             with any available SSID.
 */
typedef struct _NDIS_802_11_SSID
{
   ULONG SsidLength;
   UCHAR Ssid[32];
} NDIS_802_11_SSID, *PNDIS_802_11_SSID;
/**
 * \brief This structure contains an array of Basic Service Set (BSS) data used
 *        by NDIS_802_11_BSSID_LIST.
 * \param Length Specifies the length of the NDIS_WLAN_BSSID structure.
 * \param MacAddress Specifies a media access control (MAC) address. Each
 *                   access point has a unique MAC address that is the same
 *                   as the BSSID.
 * \param Reserved Do not use. This member maintains the DWORD alignment of the
 *                 structure.
 * \param Ssid Specifies an SSID as defined in the NDIS_802_11_SSID structure.
 * \param Privacy Specifies a WEP encryption requirement.
 * \param Rssi Specifies the Received Signal Strength Indication (RSSI) in dBm.
 * \param NetworkTypeInUse Specifies the network type as defined in the
 *                         NDIS_802_11_NETWORK_TYPE enumeration.
 * \param Configuration Specifies the radio parameter configuration as defined
 *                      in the NDIS_802_11_CONFIGURATION structure.
 * \param InfrastructureMode Specifies the infrastructure mode as defined in
 *                           the NDIS_802_11_NETWORK_INFRASTRUCTURE
 *                           enumeration.
 * \param SupportedRates Specifies a set of supported rates defined in an
 *                       NDIS_802_11_RATES array.
 */
typedef struct _NDIS_WLAN_BSSID
{
   ULONG Length;
   NDIS_802_11_MAC_ADDRESS MacAddress;
   UCHAR Reserved[2];
   NDIS_802_11_SSID Ssid;
   ULONG Privacy;
   NDIS_802_11_RSSI Rssi;
   NDIS_802_11_NETWORK_TYPE NetworkTypeInUse;
   NDIS_802_11_CONFIGURATION Configuration;
   NDIS_802_11_NETWORK_INFRASTRUCTURE InfrastructureMode;
   NDIS_802_11_RATES SupportedRates;
} NDIS_WLAN_BSSID, *PNDIS_WLAN_BSSID;
/**
 * \brief Structure used by OID_802_11_BSSID_LIST to request that a miniport
 *        driver return a list containing all basic service set identifiers
 *        (BSSIDs) and their attributes, as listed in the 802.11 NIC database.
 * \param NumberOfItems Specifies the number of items contained in the Bssid
 *                      array. This array must contain at least one item.
 * \param Bssid Specifies an array of NDIS_WLAN_BSSID structures.
 */
typedef struct _NDIS_802_11_BSSID_LIST
{
   ULONG NumberOfItems;
   NDIS_WLAN_BSSID Bssid[1];
} NDIS_802_11_BSSID_LIST, *PNDIS_802_11_BSSID_LIST;
/** @} */

/** Static adaptors list for XP mode */
static int _adaptators_list[20];
/** Static adaptors list size for XP mode */
static int _adaptators_count = 0;

/**
 * \brief Retrieve a key value from the registry.
 * \param hKey HKEY.
 * \param szPath Entry path.
 * \param szKey Key name.
 * \param szBuffer Buffer which will contains the key value.
 * \param dwSize Buffer value size.
 * \return The success of the key reading.
 */
static bool
registry_get_keyvalue(HKEY hKey, char *szPath, char *szKey, char *szBuffer,
    DWORD dwSize)
{
    HKEY rk = NULL;

    if (RegOpenKeyEx(hKey, szPath, 0, KEY_READ, &rk) != ERROR_SUCCESS)
    {
        return false;
    }

    if (RegQueryValueEx(rk,
            szKey,
            NULL,
            NULL,
            (unsigned char *)szBuffer,
            &dwSize) != ERROR_SUCCESS)
    {
        return false;
    }

    RegCloseKey(rk);
    return true;
}

/**
 * \brief Retrieve the adaptators index in an internal list.
 */
static void
retrieve_network_adaptators(void)
{
    char szKey[128];
    DWORD dwSize = 256;
    HKEY rk = NULL;
    int i = 0;

    _adaptators_count = 0;

    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE,
            "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards",
            0,
            KEY_READ,
            &rk) == ERROR_SUCCESS)
    {
        while (RegEnumKeyEx(rk,
               i,
               szKey,
               &dwSize,
               NULL,
               NULL,
               NULL,
               NULL) == ERROR_SUCCESS)
        {
            _adaptators_list[_adaptators_count] = atoi(szKey);
            _adaptators_count++;
            dwSize = 256;
            i++;
        }

        RegCloseKey(rk);
    }
}

/**
 * \brief Open a network adaptator.
 * \param szAdapterName Adaptator service name.
 * \return The adaptator handle.
 */
static HANDLE
open_adaptator(char *szAdapterName)
{
    HANDLE hAdapter;
    char szAdapter[MAX_PATH];

    _snprintf(szAdapter, sizeof(szAdapter) - 1, "\\\\.\\%s", szAdapterName);

    hAdapter = CreateFile(szAdapter,
            GENERIC_READ,
            FILE_SHARE_READ |
            FILE_SHARE_WRITE,
            NULL,
            OPEN_EXISTING,
            0,
            NULL);

    return hAdapter;
}

/**
 * \brief Get the used channel in an adaptator.
 * \param hAdapter Adaptator handle.
 * \param requested_SSID SSID that you want in priority.
 * \return The channel number or -1 if fail.
 */
static int
get_channel_from_adaptator(HANDLE hAdapter, char *requested_SSID)
{
    ULONG dwBytes, dwOIDCode;
    int i;
    NDIS_802_11_BSSID_LIST *pList;
    NDIS_802_11_SSID pBSsid;
    int _channel = -1;
    int _bestRssi = -200;

    /* If no SSID specified then attempt to retrieve the current
     * used SSID */
    if (strcmp("", requested_SSID) == 0)
    {
        /* Zerofill the SSID structure */
        memset(&pBSsid, 0, sizeof(NDIS_802_11_SSID));
        /* Set OID code to SSID request */
        dwOIDCode = OID_802_11_SSID;
        /* Used SSID request */
        DeviceIoControl(hAdapter,
            IOCTL_NDIS_QUERY_GLOBAL_STATS,
            &dwOIDCode,
            sizeof(dwOIDCode),
            &pBSsid,
            sizeof(pBSsid),
            &dwBytes,
            NULL);
        /* Set the prior SSID with the one used by the adaptator.
         * If no SSID found the value is "" */
        requested_SSID = pBSsid.Ssid;
    }

    /* Memory allocation for the network list */
    pList = (NDIS_802_11_BSSID_LIST *)VirtualAlloc(NULL,
                sizeof(NDIS_802_11_BSSID_LIST) * NUMBEROFSSIDS,
                MEM_RESERVE |
                MEM_COMMIT,
                PAGE_READWRITE);

    if (!pList)
    {
        /* Memory allocation failed then return -1 */
        return _channel;
    }
    else
    {
        /* Set OID code to BSSID_LIST_SCAN request */
        dwOIDCode = OID_802_11_BSSID_LIST_SCAN;
        /* Wifi network scanning */
        DeviceIoControl(hAdapter,
               IOCTL_NDIS_QUERY_GLOBAL_STATS,
               &dwOIDCode,
               sizeof(dwOIDCode),
               ( ULONG *)NULL,
               0,
               &dwBytes,
               NULL);

        /* Leave to breath the device ;) */
        Sleep(100);

        /* Zerofill the BSSID list */
        memset(pList, 0, sizeof(NDIS_802_11_BSSID_LIST) * NUMBEROFSSIDS);
        /* Set OID code to BSSID_LIST request */
        dwOIDCode = OID_802_11_BSSID_LIST;
        /* Retrieve the wifi networks from the previous scanning */
        if (!DeviceIoControl(hAdapter,
               IOCTL_NDIS_QUERY_GLOBAL_STATS,
               &dwOIDCode,
               sizeof(dwOIDCode),
               ( ULONG *)pList,
               sizeof(NDIS_802_11_BSSID_LIST) * NUMBEROFSSIDS,
               &dwBytes,
               NULL))
        {
            /* Scanning failed then return -1 */
            return _channel;
        }
    }

    /* Browse the BSSID list */
    for (i = 0; i < (int)pList->NumberOfItems; i++)
    {
        NDIS_WLAN_BSSID *cpSsid = &pList->Bssid[0];
        int temp = i;

        /* Get the next BSSID structure pointer.
         * ( This operation is need because the BSSID structure length
         *   is not constant )*/
        while(temp != 0)
        {
                        cpSsid=(NDIS_WLAN_BSSID *)((char*)cpSsid + cpSsid->Length);
                        temp--;
                }

        /* If the SSID of the current BSSID structure is the prior SSID
         * then get its channel */
        if (strcmp(requested_SSID, cpSsid->Ssid.Ssid) == 0)
        {
            /* Determine the channel from the radio frequency.
             * Channel = (frequency - 2407000) / 5000 */
            _channel = (cpSsid->Configuration.DSConfig - 2407000) / 5000;
            break;
        }

        /* Determine the stronger network power to return its channel if
         * no prior SSID is defined */
        if (cpSsid->Rssi > _bestRssi)
        {
            _channel = (cpSsid->Configuration.DSConfig - 2407000) / 5000;
            _bestRssi = cpSsid->Rssi;
        }
    }

    /* Return the used channel */
    return _channel;
}

/**
 * \brief Get the currently used wifi channel.
 *        You can define a prior SSID name in the first argument.
 * Return the current used channel or -1.
 */
int get_wifi_channel(char *requested_SSID)
{
    int channel = -1;
    DWORD dwVersion = 0;
    DWORD dwMajorVersion = 0;

    /* Get the Windows version. */
    dwVersion = GetVersion();
    dwMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));

    /* If the version is older than vista */
    if (dwMajorVersion < 6)
    {
        char szAdapter[128], szServiceName[128];
        HANDLE hAdapter;
        int i;

        retrieve_network_adaptators();

        for (i = 0; i < _adaptators_count; i++)
        {
            _snprintf(szAdapter, sizeof(szAdapter) - 1,
                "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards\\%d",
                _adaptators_list[i]);

            registry_get_keyvalue(HKEY_LOCAL_MACHINE,
                szAdapter,
                "ServiceName",
                szServiceName,
                sizeof(szServiceName) - 1);

            hAdapter = open_adaptator(szServiceName);

            if (hAdapter != INVALID_HANDLE_VALUE)
            {
                channel = get_channel_from_adaptator(hAdapter, requested_SSID);

                if (channel != -1)
                {
                    break;
                }
            }
        }
    }
    /* Version is vista or more recently */
    else
    {
        /*
         * This way to retrieve the Wifi channel currently used is a bit tricky.
         * Previously, an easiest code was written, but was parsing directly the
         * strings.
         * The major problem is that netsh return translated strings. So it's
         * it's almost impossible to do it working for all languages !
         *
         * This maner search for string untralsted, like SSID or BSSID, and count
         * the lines to retrieve the channel.
         */
        FILE *pcmd;
        char buff[80];
        char connected_SSID[32];
        char current_SSID[32];

        /* If no SSID specified then attempt to retrieve the current
         * used SSID */
        if (strcmp("", requested_SSID) == 0)
        {
            pcmd = popen("netsh wlan show interface", "r");

            if (pcmd != NULL)
            {
                while(fgets(buff, 80, pcmd))
                {
                    /* Parse the string : Be sure to considere the SSID line,
                     * and not BSSID */
                    if ((strstr(buff, "SSID") != NULL) &&
                        (strstr(buff, "BSSID") == NULL))
                    {
                        sscanf(strrchr(buff, ':'), ": %s", &connected_SSID[0]);
                        /* Assign the active SSID */
                        requested_SSID = connected_SSID;
                        break;
                    }
                }
                fclose(pcmd);
            }
        }

        /* Search the channel */
        pcmd = popen("netsh wlan show network mode=BSSID", "r");

        if (pcmd != NULL)
        {
            while(fgets(buff, 80, pcmd))
            {
                /* Search for the correct SSID */
                if ((strstr(buff, "SSID") != NULL) &&
                    (strstr(buff, "BSSID") == NULL))
                {
                    sscanf(strrchr(buff, ':'), ": %s", &current_SSID[0]);
                    /* If the current scanned SSID is the requested one,
                     * continue */
                    if (strcmp(current_SSID,requested_SSID) == 0)
                    {
                        break;
                    }
                }
            }
            while (fgets(buff, 80, pcmd))
            {
                /* Search for BSSID */
                if (strstr(buff, "BSSID") != NULL)
                {
                    /* Dummy reads :
                       - Signal
                       - RF type
                       */
                    fgets(buff, 80, pcmd);
                    fgets(buff, 80, pcmd);

                    /* Retrive the channel */
                    fgets(buff, 80, pcmd);
                    sscanf(strrchr(buff, ':'), ": %d", &channel);

                    break;
                }
            }
            fclose(pcmd);
        }
    }
    return channel;
}

/**
 * \brief Program entry point.
 *        You can define a prior SSID name in the first argument.
 * Return the current used channel or -1.
 */
int main(int argc, char *argv[])
{
    char *requested_SSID = "";

    /* Set SSID name to search */
    if (argc > 1)
    {
        requested_SSID = argv[1];
    }
    printf("Wifi channel is : %d\n", get_wifi_channel(requested_SSID));
    return get_wifi_channel(requested_SSID);
}
</pre></div><div>

소스 출처 : http://svn.tuxisalive.com/software_suite_v2/software/tux_wifi_channel/