C++ - Detours WinSock Hooking

5
我想要做的是使用Detours库来钩取一个应用程序中的WinSock2 send()和recv() 函数(数据包记录器)。
尽管它可以使用于send()函数,但是无法使用在recv()函数上。
以下是相关代码:
#include <cstdio>
#include <ctime>
#include <fstream>
#include <iomanip>
#include <string>
#include <windows.h>
#include <detours.h>

#pragma comment( lib, "Ws2_32.lib" )
#pragma comment( lib, "detours.lib" )
#pragma comment( lib, "detoured.lib" )
#pragma comment( lib, "Mswsock.lib" )

std::ofstream Logger;

std::string NowToString() {
    time_t rawtime;
    tm *timeinfo = new tm();
    char buffer[32];

    time( &rawtime );
    localtime_s( timeinfo, &rawtime );

    strftime( buffer, 32, "%m/%d/%Y %I:%M:%S %p", timeinfo );

    delete timeinfo;

    return std::string( buffer );
}

std::string TimeToString() {
    time_t rawtime;
    tm *timeinfo = new tm();
    char buffer[32];

    time( &rawtime );
    localtime_s( timeinfo, &rawtime );

    strftime( buffer, 32, "%I:%M:%S %p", timeinfo );

    delete timeinfo;

    return std::string( buffer );
}

void LogPacket( const char *buf, int len ) {
    Logger << "        0  1  2  3  4  5  6  7   8  9  A  B  C  D  E  F\n";
    Logger << "       -- -- -- -- -- -- -- --  -- -- -- -- -- -- -- --\n";
    Logger << "0000   ";

    for ( int i = 0; i < len; ++i ) {
        if ( i != 0 && i % 16 == 0 ) {
            Logger << "  ";

            int line = ( i / 16 ) - 1;

            for ( int j = 0; j < 16; ++j ) {
                char c = buf[line * 16 + j];

                if ( c >= 32 && c <= 126 ) {
                    Logger << c;
                } else {
                    Logger << '.';
                }
            }

            Logger << "\n" << std::hex << std::setw( 4 ) << std::setfill( '0' ) << i << std::dec << std::setw( 0 ) << "   ";
        } else if ( i % 16 == 8 ) {
            Logger << ' ';
        }

        Logger << std::hex << std::setw( 2 ) << std::setfill( '0' ) << ( int( buf[i] ) & 0xFF ) << ' ';
        Logger << std::dec << std::setw( 0 );

        if ( i == len - 1 ) {
            int remaining = 16 - ( len % 16 );
            int fill = ( remaining * 3 ) + 2;

            if ( remaining >= 8 ) {
                ++fill;
            }

            for ( int j = 0; j < fill; ++j ) {
                Logger << ' ';
            }

            int line = ( i - ( ( len % 16 ) - 1 ) ) / 16 ;

            for ( int k = 0; k < ( len % 16 ); ++k ) {
                char c = buf[line * 16 + k];

                if ( c >= 32 && c <= 126 ) {
                    Logger << c;
                } else {
                    Logger << '.';
                }
            }
        }
    }

    Logger << "\n\n";
}

int ( WINAPI *Real_Send )( SOCKET s, const char *buf, int len, int flags ) = send;
int ( WINAPI *Real_Recv )( SOCKET s, char *buf, int len, int flags ) = recv;
int ( WINAPI *Real_RecvFrom )( SOCKET s, char *buf, int len, int flags, sockaddr *from, int *fromlen ) = recvfrom;
int ( WINAPI *Real_WSARecvEx )( SOCKET s, char *buf, int len, int *flags ) = WSARecvEx;

int WINAPI Mine_Send( SOCKET s, const char* buf, int len, int flags );
int WINAPI Mine_Recv( SOCKET s, char *buf, int len, int flags );
int WINAPI Mine_RecvFrom( SOCKET s, char *buf, int len, int flags, sockaddr *from, int *fromlen );
int WINAPI Mine_WSARecvEx( SOCKET s, char *buf, int len, int *flags );

int WINAPI Mine_Send( SOCKET s, const char *buf, int len, int flags ) {
    Logger << TimeToString() << ": Client -> Server (Length: " << len << " bytes)\n\n";
    LogPacket( buf, len );
    Logger << std::endl;

    return Real_Send( s, buf, len, flags );
}

int WINAPI Mine_Recv( SOCKET s, char *buf, int len, int flags ) {
    Logger << TimeToString() << ": Server -> Client (Length: " << len << " bytes)\n\n";
    LogPacket( buf, len );
    Logger << std::endl;

    return Real_Recv( s, buf, len, flags );
}

int WINAPI Mine_RecvFrom( SOCKET s, char *buf, int len, int flags, sockaddr *from, int *fromlen ) {
    Logger << TimeToString() << ": Server -> Client (Length: " << len << " bytes)*\n\n";
    LogPacket( buf, len );
    Logger << std::endl;

    return Real_RecvFrom( s, buf, len, flags, from, fromlen );
}

int WINAPI Mine_WSARecvEx( SOCKET s, char *buf, int len, int *flags ) {
    Logger << TimeToString() << ": Server -> Client (Length: " << len << " bytes)**\n\n";
    LogPacket( buf, len );
    Logger << std::endl;

    return Real_WSARecvEx( s, buf, len, flags );
}

BOOL WINAPI DllMain( HINSTANCE, DWORD dwReason, LPVOID ) {
    switch ( dwReason ) {
        case DLL_PROCESS_ATTACH:    
            Logger.open( "C:\\Packets.txt", std::ios::out | std::ios::app | std::ios::ate );

            if ( Logger.tellp() > 0 ) {
                Logger << "\n\n\n";
            }

            Logger << "##\n## Logging Started (" << NowToString() << ")\n##\n\n\n";

            DetourTransactionBegin();
            DetourUpdateThread( GetCurrentThread() );
            DetourAttach( &(PVOID &)Real_Send, Mine_Send );
            DetourAttach( &(PVOID &)Real_Recv, Mine_Recv );
            DetourAttach( &(PVOID &)Real_RecvFrom, Mine_RecvFrom );
            DetourAttach( &(PVOID &)Real_WSARecvEx, Mine_WSARecvEx );
            DetourTransactionCommit();

            break;

        case DLL_PROCESS_DETACH:
            Logger << "##\n## Logging Stopped (" << NowToString() << ")\n##";
            Logger.close();

            DetourTransactionBegin();
            DetourUpdateThread( GetCurrentThread() );
            DetourDetach( &(PVOID &)Real_Send, Mine_Send );
            DetourDetach( &(PVOID &)Real_Recv, Mine_Recv );
            DetourDetach( &(PVOID &)Real_RecvFrom, Mine_RecvFrom );
            DetourDetach( &(PVOID &)Real_WSARecvEx, Mine_WSARecvEx );
            DetourTransactionCommit();

            break;
    }

    return TRUE;
}

有什么想法吗?

编辑:所以我已经钩住了recvfrom()和WSARecvEx(),但仍然无法记录出站数据包!我已经更新了我的代码,包括我的确切代码。

2个回答

4
为了有效地使用钩子技术,您需要确保真正挂钩所有相关的端点或至少一个公共分母,可以确保从所有端点最终调用它。
recv()的情况下,我认为应用程序实际上会调用WSARecv()
您可以使用depends.exe来确定应用程序/库从Ws2_32.dll导入了哪些函数,以知道您需要挂钩哪些函数。

我做了这件事,它使用了3个函数:recv()、recvfrom()和WSARecvEx()。顺便说一句:我以为send()和recv()总是被调用的,即使是从WSARecv()和其他类似的函数中,也许我想错了! - xian

4

几个月后,我终于明白了:当我应该钩取WinSock 1.1的send()/recv()函数时,我却钩取了WinSock 2的函数!


2
如何选择要挂钩哪个版本? - methyl
@methyl 抱歉我有点晚了,但你应该知道你的应用程序使用哪个版本。如果你在x32dbg中打开你的应用程序,请转到符号选项卡并检查是否看到ws2_32.dll。如果你看到它,那么它可能是Winsocks2,如果是,它可能是Winsocks1。 - Keytrap

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