winpcap demo

最近要写一个程序捕获物理层的包，用到了winpcap，使用很简单。
详见：http://www.cnblogs.com/phinecos/archive/2008/10/20/1315176.html。

// Demo.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#define HAVE_REMOTE#include <pcap.h>#define GET_ADAPTER_LIST#define GET_PACKET#define SEND_PACKET#pragma comment(lib,"wpcap.lib")#pragma comment(lib,"Packet.lib")int _tmain(int argc, _TCHAR* argv[]){#ifdef GET_ADAPTER_LIST    pcap_if_t * allAdapters;//适配器列表    pcap_if_t * adapter;    char errorBuffer[ PCAP_ERRBUF_SIZE ];//错误信息缓冲区    if( pcap_findalldevs_ex( PCAP_SRC_IF_STRING, NULL,                 &allAdapters, errorBuffer ) == -1 )    {//检索机器连接的所有网络适配器        fprintf( stderr, "Error in pcap_findalldevs_ex function: %s\n", errorBuffer );        return -1;    }    if( allAdapters == NULL )    {//不存在人任何适配器        printf( "\nNo adapters found! Make sure WinPcap is installed.\n" );        return 0;    }    int crtAdapter = 0;    for( adapter = allAdapters; adapter != NULL; adapter = adapter->next)    {//遍历输入适配器信息(名称和描述信息)        printf( "\n%d.%s ", ++crtAdapter, adapter->name );        printf( "-- %s\n", adapter->description );    }    printf( "\n" );    pcap_freealldevs( allAdapters );//释放适配器列表    system( "PAUSE" );#elif defined GET_PACKET    pcap_if_t * allAdapters;//适配器列表    pcap_if_t * adapter;    pcap_t           * adapterHandle;//适配器句柄    struct pcap_pkthdr * packetHeader;    const u_char       * packetData;    char errorBuffer[ PCAP_ERRBUF_SIZE ];//错误信息缓冲区    if( pcap_findalldevs_ex( PCAP_SRC_IF_STRING, NULL,                 &allAdapters, errorBuffer ) == -1 )    {//检索机器连接的所有网络适配器        fprintf( stderr, "Error in pcap_findalldevs_ex function: %s\n", errorBuffer );        return -1;    }    if( allAdapters == NULL )    {//不存在任何适配器        printf( "\nNo adapters found! Make sure WinPcap is installed.\n" );        return 0;    }    int crtAdapter = 0;    for( adapter = allAdapters; adapter != NULL; adapter = adapter->next)    {//遍历输入适配器信息(名称和描述信息)        printf( "\n%d.%s ", ++crtAdapter, adapter->name );         printf( "-- %s\n", adapter->description );    }    printf( "\n" );    //选择要捕获数据包的适配器    int adapterNumber;    printf( "Enter the adapter number between 1 and %d:", crtAdapter );    scanf_s( "%d", &adapterNumber );    if( adapterNumber < 1 || adapterNumber > crtAdapter )    {        printf( "\nAdapter number out of range.\n" );        // 释放适配器列表        pcap_freealldevs( allAdapters );        return -1;    }    adapter = allAdapters;    for( crtAdapter = 0; crtAdapter < adapterNumber - 1; crtAdapter++ )    adapter = adapter->next;    // 打开指定适配器    adapterHandle = pcap_open( adapter->name, // name of the adapter                               65536,         // portion of the packet to capture                                              // 65536 guarantees that the whole                           // packet will be captured                               PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode                               1000,             // read timeout - 1 millisecond                               NULL,          // authentication on the remote machine                               errorBuffer    // error buffer                              );    if( adapterHandle == NULL )    {//指定适配器打开失败        fprintf( stderr, "\nUnable to open the adapter\n", adapter->name );        // 释放适配器列表        pcap_freealldevs( allAdapters );        return -1;    }    printf( "\nCapture session started on  adapter %s\n", adapter->name );    pcap_freealldevs( allAdapters );//释放适配器列表    // 开始捕获数据包    int retValue;    while( ( retValue = pcap_next_ex( adapterHandle,                       &packetHeader,                       &packetData ) ) >= 0 )    {        // timeout elapsed if we reach this point        if( retValue == 0 )                continue;        //打印捕获数据包的信息        printf( "length of packet: %d\n", packetHeader->len );    }    // if we get here, there was an error reading the packets    if( retValue == -1 )    {        printf( "Error reading the packets: %s\n", pcap_geterr( adapterHandle ) );        return -1;    }    system( "PAUSE" );#elif defined SEND_PACKET    pcap_if_t * allAdapters;//适配器列表    pcap_if_t * adapter;    pcap_t           * adapterHandle;//适配器句柄    u_char         packet[ 20 ]; //待发送的数据封包    char errorBuffer[ PCAP_ERRBUF_SIZE ];//错误信息缓冲区    if( pcap_findalldevs_ex( PCAP_SRC_IF_STRING, NULL,                 &allAdapters, errorBuffer ) == -1 )    {//检索机器连接的所有网络适配器        fprintf( stderr, "Error in pcap_findalldevs_ex function: %s\n", errorBuffer );        return -1;    }    if( allAdapters == NULL )    {//不存在人任何适配器        printf( "\nNo adapters found! Make sure WinPcap is installed.\n" );        return 0;    }    int crtAdapter = 0;    for( adapter = allAdapters; adapter != NULL; adapter = adapter->next)    {//遍历输入适配器信息(名称和描述信息)        printf( "\n%d.%s ", ++crtAdapter, adapter->name );         printf( "-- %s\n", adapter->description );    }    printf( "\n" );    //选择适配器    int adapterNumber;    printf( "Enter the adapter number between 1 and %d:", crtAdapter );    scanf_s( "%d", &adapterNumber );    if( adapterNumber < 1 || adapterNumber > crtAdapter )    {        printf( "\nAdapter number out of range.\n" );        // 释放适配器列表        pcap_freealldevs( allAdapters );        return -1;    }    adapter = allAdapters;    for( crtAdapter = 0; crtAdapter < adapterNumber - 1; crtAdapter++ )    adapter = adapter->next;    // 打开指定适配器    adapterHandle = pcap_open( adapter->name, // name of the adapter                               65536,         // portion of the packet to capture                                              // 65536 guarantees that the whole                           // packet will be captured                               PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode                               1000,             // read timeout - 1 millisecond                               NULL,          // authentication on the remote machine                               errorBuffer    // error buffer                              );    if( adapterHandle == NULL )    {//指定适配器打开失败        fprintf( stderr, "\nUnable to open the adapter\n", adapter->name );        // 释放适配器列表        pcap_freealldevs( allAdapters );        return -1;    }    pcap_freealldevs( allAdapters );//释放适配器列表    //创建数据封包    // 设置目标的MAC地址为01 : 01 : 01 : 01 : 01 : 01    packet[0] = 0x01;    packet[1] = 0x01;    packet[2] = 0x01;    packet[3] = 0x01;    packet[4] = 0x01;    packet[5] = 0x01;    // 设置源的MAC地址为02 : 02 : 02 : 02 : 02 : 02    packet[6]  = 0x02;    packet[7]  = 0x02;    packet[8]  = 0x02;    packet[9]  = 0x02;    packet[10] = 0x02;    packet[11] = 0x02;    // 设置封包其他部分内容    for( int index = 12; index < 20; index++ )    {        packet[index] = 0xC4;    }    //发送数据封包    if( pcap_sendpacket( adapterHandle, // the adapter handle             packet, // the packet             20 // the length of the packet               ) != 0 )    {        fprintf( stderr,"\nError sending the packet: \n", pcap_geterr( adapterHandle ) );        return -1;    }    system( "PAUSE" );#endif    return 0;}