C++ - 绕道WinSock Hooking

Question

我想做的是使用 Detours 库 挂钩应用程序 WinSock2 send() 和 receive() 函数（数据包记录器）。

虽然它确实适用于 send() 函数，但它不适用于 receive() 函数。

这是我的相关代码：

#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：所以我也挂钩了recvfrom()和WSARecvEx()，但它仍然不记录传出的数据包！ 我已经用我的确切代码更新了我的代码。

Answer 1

要有效地使用挂钩，您需要确保真正挂钩所有相关端点或至少确保最终从所有端点调用一个共同点。
对于 recv() ，我认为应用程序实际上可能调用 WSARecv() 。
您可以使用 depends.exe 来准确找出应用程序/库从 Ws2_32.dll 导入哪些函数知道你需要钩住哪些。

Answer 2

好吧，几个月后我想通了：当我应该挂钩 WinSock 1.1 的 send()/recv() 时，我却挂钩了 WinSock 2 函数！