/* 
 *  rocks/insert_code.c
 *
 *  Inserts code into the child process to load the rocks library.
 *  Uses file entry.bin and preload.bin generated by NASM.
 *
 *  Copyright (C) 2001 Victor Zandy, Greg Quinn
 *  See COPYING for distribution terms.
 */

#include <windows.h>
#include <assert.h>
#include "insert_code.h"

BOOL insert_code(DWORD entry_address, DWORD preload_address,
				 PBYTE old_entry_code, HANDLE process) {

	HRSRC entry_rsrc, preload_rsrc;
	HGLOBAL entry_glob, preload_glob;
	PBYTE entry_code, preload_code;
	DWORD rv;
	PROC tmp_proc;

printf("inserting code, dude!\n");
	/* insert the entry code */
	entry_rsrc = FindResource(GetModuleHandle(NULL), TEXT("ENTRY"),
	                          TEXT("ENTRY_TYPE"));
	entry_glob = LoadResource(GetModuleHandle(NULL), entry_rsrc);
	entry_code = LockResource(entry_glob);
printf("found entry code %p: %.02x%.02x%.02x%.02x\n", entry_code, entry_code[0], entry_code[1], entry_code[2], entry_code[3]);
	rv = preload_address + PRELOAD_START_OFFSET;
	memcpy(&entry_code[EP_PRELOAD_ADDRESS], &rv, 4);
	WriteProcessMemory(process, (PCHAR)NULL + entry_address, entry_code,
	                   ENTRY_BIN_SIZE, &rv);
	assert(rv == ENTRY_BIN_SIZE);
	FreeResource(entry_code);

	/* insert the preload code */
	preload_rsrc = FindResource(GetModuleHandle(NULL), TEXT("PRELOLD"),
	                            TEXT("PRELOLD_TYPE"));
	preload_glob = LoadResource(GetModuleHandle(NULL), preload_rsrc);
	preload_code = LockResource(preload_glob);
printf("found preload code %p: %.02x%.02x%.02x%.02x\n", preload_code, preload_code[0], preload_code[1], preload_code[2], preload_code[3]);
	memcpy(&preload_code[PP_OLD_ENTRY_BUF], old_entry_code, ENTRY_BIN_SIZE);
	tmp_proc = (PROC)LoadLibrary;
	memcpy(&preload_code[PP_LOAD_LIBRARY], &tmp_proc, 4);
	memcpy(&preload_code[PP_ENTRY_POINT_1], &entry_address, 4);
	tmp_proc = (PROC)GetCurrentProcess;
	memcpy(&preload_code[PP_GET_CURRENT_PROCESS], &tmp_proc, 4);
	tmp_proc = (PROC)WriteProcessMemory;
	memcpy(&preload_code[PP_WRITE_PROCESS_MEMORY], &tmp_proc, 4);
	memcpy(&preload_code[PP_ENTRY_POINT_2], &entry_address, 4);
	rv = preload_address + P_ROCKSDLL;
	memcpy(&preload_code[PP_DLLSTRING_ADDRESS], &rv, 4);
	rv = preload_address + PP_OLD_ENTRY_BUF;
	memcpy(&preload_code[PP_OLD_ENTRY_ADDRESS], &rv, 4);
printf("writing process memory\n");

	WriteProcessMemory(process, (PCHAR)NULL + preload_address, preload_code,
	                   PRELOAD_BIN_SIZE, &rv);
	FreeResource(preload_code);
printf("finished\n");

	return TRUE;
}