#include <Windows.h>
#include <iostream>

//--------------------импортируем функции testlib.dll--------------------------
#pragma comment(lib,"..\\debug\\testlib.lib") 
extern "C" int WINAPI test(int x); 
//-----------------------------------------------------------------------------------

int main(char*, char*)
{
	//LoadLibrary(L"patcher.dll"); //какимто волшебным образом грузим патч

	getchar();
	test(0);
	getchar();
	return 0;
};

#include <Windows.h>
#include <iostream>

int WINAPI DllMain(HINSTANCE hInstance, DWORD fdReason, PVOID pvReserved)
{	
	return TRUE;
};

extern "C" int WINAPI test(int x) //экспорт
{
        if (x==0)
	    {
		printf("street magic failed\n");
	    }
	else if (x==1)
	   {
		printf("oO pechen'ki \n");
	   }
	else
	   {
		printf("crazy magic \n");
	   };

        return 0;
};

LIBRARY	"testlib"
EXPORTS
test @666

.text:1001108C                 jmp     test_0    //это возвращает GetProcAddres
..............
......
..............
.text:10011380
.text:10011380 ; =============== S U B R O U T I N E =======================================
.text:10011380
.text:10011380 ; Attributes: bp-based frame
.text:10011380
.text:10011380 test_0          proc near               ; CODE XREF: testj
.text:10011380
.text:10011380 var_C0          = byte ptr -0C0h
.text:10011380 arg_0           = dword ptr  8
.text:10011380
.text:10011380                 push    ebp
.text:10011381                 mov     ebp, esp
.text:10011383                 sub     esp, 0C0h
.text:10011389                 push    ebx
.text:1001138A                 push    esi
.text:1001138B                 push    edi
.text:1001138C                 lea     edi, [ebp+var_C0]
.text:10011392                 mov     ecx, 30h
.text:10011397                 mov     eax, 0CCCCCCCCh
.text:1001139C                 rep stosd
.text:1001139E                 cmp     [ebp+arg_0], 0
.text:100113A2                 jnz     short loc_100113BD
.text:100113A4                 mov     esi, esp
.text:100113A6                 push    offset aStreetMagicFai ; "street magic failed\n"
.text:100113AB                 call    ds:__imp__printf  
.text:100113B1                 add     esp, 4
.text:100113B4                 cmp     esi, esp
.text:100113B6                 call    j__RTC_CheckEsp
.text:100113BB                 jmp     short loc_100113F3
.text:100113BD ; ---------------------------------------------------------------------------
.text:100113BD
.text:100113BD loc_100113BD:                           ; CODE XREF: test_0+22j
.text:100113BD                 cmp     [ebp+arg_0], 1
.text:100113C1                 jnz     short loc_100113DC
.text:100113C3                 mov     esi, esp
.text:100113C5                 push    offset aOoPechenKi ; "oO pechen'ki \n"
.text:100113CA                 call    ds:__imp__printf  ;интересует этот случай
.text:100113D0                 add     esp, 4
.text:100113D3                 cmp     esi, esp
.text:100113D5                 call    j__RTC_CheckEsp
.text:100113DA                 jmp     short loc_100113F3
.text:100113DC ; ---------------------------------------------------------------------------
.text:100113DC
.text:100113DC loc_100113DC:                           ; CODE XREF: test_0+41j
.text:100113DC                 mov     esi, esp
.text:100113DE                 push    offset aCrazyMagic ; "crazy magic \n"
.text:100113E3                 call    ds:__imp__printf
.text:100113E9                 add     esp, 4
.text:100113EC                 cmp     esi, esp
.text:100113EE                 call    j__RTC_CheckEsp
.text:100113F3
.text:100113F3 loc_100113F3:                           ; CODE XREF: test_0+3Bj
.text:100113F3                                         ; test_0+5Aj
.text:100113F3                 xor     eax, eax
.text:100113F5                 pop     edi
.text:100113F6                 pop     esi
.text:100113F7                 pop     ebx
.text:100113F8                 add     esp, 0C0h
.text:100113FE                 cmp     ebp, esp
.text:10011400                 call    j__RTC_CheckEsp
.text:10011405                 mov     esp, ebp
.text:10011407                 pop     ebp
.text:10011408                 retn    4
.text:10011408 test_0          endp
.text:10011408
.text:10011408; ---------------------------------------------------------------------------

#include <Windows.h>
typedef int (WINAPI *testEx)(int x);

extern "C" int WINAPI fakeprintf(char* data)
{
//тут будут всякие шаманства
//
//
return 0;
};


int WINAPI DllMain(HINSTANCE hInstance, DWORD fdReason, PVOID pvReserved)
{
	LPWCH name = new WCHAR[MAX_PATH];
	GetModuleFileNameW(0,name, MAX_PATH);
	MessageBox(0,name,L"запустилась",MB_OK);//тут будет проверка name

	HMODULE hlib = GetModuleHandle(L"testlib");
	testEx f =  (testEx)GetProcAddress(hlib,"test");//f=0x1001108C
     //и тут типа закончилась фантазия......
     //......пойду убьюсь

return TRUE;
};

LIBRARY	"patcher"
EXPORTS
fakeprintf @1

.100113CA  FF156C820110      call      printf ; MSVCR80D.dll

0000A4D2: FF2528397210                 jmp       d,[10723928]; джамп на send из wsock32
---
-
---
00015BBB: 50                           push      eax
00015BBC: 51                           push      ecx
00015BBD: E81049FFFF                   call      00000A4D2 ; нужный вызов
00015BC2: 8BF0                         mov       esi,eax