code: /*
   * Copyright (c) 2014, Aleksander Osman
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 
   * * Redistributions of source code must retain the above copyright notice, this
   *   list of conditions and the following disclaimer.
   * 
   * * Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package ao486.test.layers;
  
  import java.util.HashMap;
  import java.util.LinkedList;
  import java.util.Random;
  
  public class StackLayer extends Layer {
      public StackLayer(Random random, LinkedList<Pair<Long, Long>> prohibited_list) {
          this.random = random;
          
          ss_d_b = random.nextBoolean();
          
          while(true) {
              ss_base = norm(random.nextInt());
  
              ss_limit = random.nextInt(ss_d_b? 0xFFFFF + 1 : 0xFFFF + 1);
              
              if( ss_base + ss_limit < 4294967296L &&
                  collides(prohibited_list, ss_base, ss_base + ss_limit) == false    
              ) break;
          }
          esp = random.nextInt((int)ss_limit + 1);
          ss_index = ss_base + esp;
          
          if(ss_d_b == false) {
              esp |= random.nextInt() & 0xFFFF0000;
          }
          
          prohibited_list.add(new Pair<>(ss_base, ss_base+ss_limit));
      }
      public void push_byte(int value) {
  //System.out.printf("push_byte: %08x :: %08x\n", ss_index, value);
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)(value & 0xFF));
          ss_index++;
      }
      public void push_word(int value) {
  //System.out.printf("push_word: %08x :: %08x\n", ss_index, value);
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)(value & 0xFF));
          ss_index++;
          
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)((value >> 8) & 0xFF));
          ss_index++;
      }
      public void push_dword(int value) {
  //System.out.printf("push_dword: %08x :: %08x\n", ss_index, value);
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)(value & 0xFF));
          ss_index++;
          
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)((value >> 8) & 0xFF));
          ss_index++;
          
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)((value >> 16) & 0xFF));
          ss_index++;
          
          if(ss_index > ss_base + ss_limit) return;
          ss_map.put(ss_index, (byte)((value >> 24) & 0xFF));
          ss_index++;
      }
      
      //-----------
      
      public long esp() {
          return esp;
      }
      public long ss_base() {
          return ss_base;
      }
      public long ss_limit() {
          return ss_limit;
      }
      public long ss_d_b() {
          return ss_d_b? 1 : 0;
      }
      public boolean is_memory_not_random(long address) { return ss_map.containsKey(address); }
      
      public Byte get_memory(long address) {
          if(address < ss_base || address > ss_base + ss_limit) return null;
          
          if(ss_map.containsKey(address)) return ss_map.get(address);
          
          return (byte)random.nextInt();
      }
      
      HashMap<Long, Byte> ss_map = new HashMap<>();
      boolean ss_d_b;
      long ss_base, ss_limit, ss_index;
      long esp;
  }
  