Modified Autoconnect.cpp

/*
  Autoconnect.cpp - Directly connect to a server upon starting the game.

  Jason Hood, 1 September, 2016.

  Usage:
    Add "-I[server[:password]]" (internet) or "-L[server[:password]]" (LAN)
    to automatically connect to that server.  Server may be either the name
    or address; only a prefix is necessary (whatever matches first).  If
    password is absent, it will be prompted as usual.

  Install:
    Copy Autoconnect.dll to your EXE directory and add it to the
    [Libraries] section of dacom.ini.
*/

#include "patch.h"
#include <string>
using std::wstring;

#define ADDR_MENU   0x575360
#define ADDR_SERVER (0x56FF59+1)
#define ADDR_PASSWORD   ((PDWORD)(0x5721A8+1))
#define ADDR_INTERNET   ((bool*)0x615B10)
#define ADDR_VERSION    ((PDWORD)0x67ECB8)

wstring server, password;

struct Connection   // partial
{
    UINT dunno1;
    wchar_t* addr;
    BYTE stuff[16 * 4];
    wchar_t* name;
    BYTE more[16 * 4];
    DWORD version;
};

DWORD Menu_Old;

NAKED
void Menu_Hook( void )
{
    __asm {
        mov eax, Menu_Old
        mov ds:[ADDR_MENU], eax // restore the menu
        jmp dword ptr ds:[ADDR_MENU+12] // Multiplayer state
        align 16
    }
}

bool FASTCALL SvrTest( const Connection& srvr )
{
    return (srvr.version == *ADDR_VERSION &&
            (_wcsnicmp( srvr.name, server.c_str(), server.length()) == 0 ||
            _wcsnicmp( srvr.addr, server.c_str(), server.length()) == 0));
}

DWORD Server_Old, Server_Org;

NAKED
void Server_Hook( void )
{
    __asm {
        cmp dword ptr [esi+0x114], 1
        je done
        push ecx
        push eax
        mov ecx, eax
        call SvrTest
        test al, al
        pop eax
        pop ecx
        jz done
        mov edx, Server_Org
        mov dword ptr [esi+0x114], 1
        mov ds:[ADDR_SERVER], edx
        mov edx, 0x572100
        push eax
        call edx
        mov edx, 0x571FC0
        mov ecx, esi
        call edx
        ret 8
    done:
        jmp Server_Old
        align 16
    }
}

DWORD Password_Old, Password_Org;

struct vc6wstring
{
    UINT allocator;
    const wchar_t* ptr;
    size_t len, res;
};

bool Password_Hook( UINT, vc6wstring& pwd, UINT, UINT )
{
    *ADDR_PASSWORD = Password_Org;
    wchar_t* sz = new wchar_t[password.capacity()];
    memcpy_s(sz, password.capacity() * sizeof(wchar_t), password.c_str(), (password.size() + 1) * sizeof(wchar_t));
    pwd.ptr = sz;
    pwd.len = password.size();
    pwd.res = password.capacity();
    return true;
}


void Patch()
{
    ProtectX( (PVOID)ADDR_MENU,  4 );
    ProtectX( (PVOID)ADDR_SERVER, 4 );

    Server_Org = *(PDWORD)ADDR_SERVER;

    NEWABS( (PDWORD)ADDR_MENU,   Menu );
    NEWOFS( (PDWORD)ADDR_SERVER, Server );

    if (!password.empty())
    {
        ProtectX( ADDR_PASSWORD, 4 );
        Password_Org = *ADDR_PASSWORD;
        NEWOFS( ADDR_PASSWORD, Password );
    }
}


BOOL WINAPI DllMain( HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved )
{
    if (fdwReason == DLL_PROCESS_ATTACH)
    {
        LPCWSTR cmdline = GetCommandLineW();
        while (*cmdline != '\0')
        {
            if (*cmdline == ' ' && cmdline[1] == '-' &&
                (cmdline[2] == 'I' || cmdline[2] == 'L'))
            {
                if (cmdline[2] == 'L')
                    *ADDR_INTERNET = false;
                int len = 0;
                cmdline += 3;
                while (cmdline[len] > ' ' && cmdline[len] != ':')
                    ++len;
                server.assign( cmdline, len );
                if (cmdline[len] == ':')
                {
                    cmdline += len + 1;
                    len = 0;
                    while (cmdline[len] > ' ')
                        ++len;
                    password.assign( cmdline, len );
                }
                Patch();
            }
            ++cmdline;
        }
    }

    return TRUE;
}