blackmarket/blackmarket.c

//gcc -m32 -fno-stack-protector -z execstack -no-pie blackmarket.c -o blackmarket
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <time.h>
#include "blackmarket.h"

#define BUFSIZE 0x1ff

int diamond;

void not_used(){
  system("/bin/sh");
}

Node *Node_create(){
  Node *node = malloc(sizeof(Node));

  assert(node != NULL);
  
  node->data = "";
  node->next = NULL;
}

List *List_create(){
  List *list = malloc(sizeof(List));
  assert(list != NULL);

  Node *node = Node_create();
  list->first = node;
  return list;
}

void List_append(List *list, char *str){
  assert(list != NULL);
  assert(str != NULL);

  Node *node = list->first;
  while(node->next != NULL){
    node = node->next;
  }
  node->data = str;
  node->next = Node_create();
}

int List_find(List *list, char *str){
  assert(list != NULL);
  assert(str != NULL);

  int index = 0;
  Node *node = list->first;
  while(node->next != NULL){
    int cmp = strcmp(str, node->data);
    if(cmp == 0){
      return index;
    }
    node = node->next;
    index++;
  }
  return -1;
}

int List_length(List *list){
  assert(list != NULL);

  Node *node = list->first;
  int length = 0;
  while(node->next != NULL){
    length++;
    node = node->next;
  }
  return length;
}

void Node_destroy(Node *node){
  assert(node != NULL);
  free(node);
}

void List_remove(List *list, int index){
  assert(list != NULL);
  if(index < 0){
    exit(0);
  }else{
    assert(index < List_length(list));
  
    if(index == 0){
      Node *node = list->first;
      list->first = list->first->next;
      Node_destroy(node);
    }else{
      Node *before = list->first;
      for(int i=1; i<index; ++i){
        before = before->next;
        index--;
      }
      Node *node = before->next;
      before->next = before->next->next;
      Node_destroy(node);
    }
  }
}

void List_print(List *list){
  if(list != NULL){
    printf("[");
    Node *node = list->first;
    if(node->next == NULL){
      printf("NULL");
    }
    while(node->next != NULL){
      printf("%s", node->data);
      node = node->next;
      if (node->next != NULL){
        printf(", ");
      }
    }
    printf("]\n");
  }
}

int sell_item(char *item){
  int current_wallet = 0;

  if(strcmp(item, "potatoes") == 0){
    printf("You've earn 50 wallet!\n");
    current_wallet = 50;
    return current_wallet;
  }else if(strcmp(item, "grape") == 0){
    printf("You've earn 100 wallet!\n");
    current_wallet = 100;
    return current_wallet;
  }else if(strcmp(item, "apel") == 0){
    printf("You've earn 60 wallet!\n");
    current_wallet = 60;
    return current_wallet;
  }
}

void message(){
  printf("You don't have enough wallet!\n");
}

void success_msg(char *item){
  printf("%s added to the list!\n", item);
}

void menu(){

  printf("+-----------------------+\n");
  printf("MASSIVE BLACKMARKET STORE\n");
  printf("+-----------------------+\n");
  printf("1. buy flag (200 Diamond)\n");
  printf("2. buy potatoes (50 Wallet)\n");
  printf("3. buy grape (100 Wallet)\n");
  printf("4. buy apel (60 Wallet)\n");
  printf("5. show items\n");
  printf("6. sell items\n");
  printf("7. check wallet\n");
  printf("8. check diamond\n");
  printf("9. get free diamond!\n");
  printf("10. exit\n");
}

int main(){
   
  List *l = List_create();
  char buffer[BUFSIZE+1], ans[2];
  int wallet = 300, temp, try = 0;
  
  LOOP:while(1){
    menu();
    printf(">>");
    fflush(stdout);
    scanf("%s", &ans);
    if(strcmp(ans, "1") == 0){ 
      if(diamond < 200){
        printf("Not enough diamond to buy flag!\nnothing to add.\n");
        goto LOOP;
      }else if(diamond >= 200){
        diamond = diamond - 200;
        List_append(l, "flag");
        success_msg("flag");
        goto LOOP;
      }
    }else if(strcmp(ans, "2") == 0){
      if(wallet < 50){
        message();
        goto LOOP;
      }
      success_msg("potatoes");
      wallet = wallet - 50;
      List_append(l, "potatoes");
      goto LOOP;
    }else if(strcmp(ans, "3") == 0){
      if(wallet < 100){
        message();
        goto LOOP;
      }
      success_msg("grape");
      wallet = wallet - 100;
      List_append(l, "grape");
      goto LOOP;
    }else if(strcmp(ans, "4") == 0){
      if(wallet < 60){
        message();
        goto LOOP;
      }
      success_msg("apel");
      wallet = wallet - 60;
      List_append(l, "apel");
      goto LOOP;
    }else if(strcmp(ans, "5") == 0){
      printf("\nYour Items :\n");
      List_print(l);
      goto LOOP;
    }else if(strcmp(ans, "6") == 0){
      getchar();
      printf("What items you want to sell ?\n");
      fflush(stdout);
      fgets(buffer, sizeof(buffer), stdin); 
      printf("You sell : ");
      printf(buffer);
      strtok(buffer, "\n"); 
      int check = List_find(l, buffer);
      if(check == (-1)){
        printf("Not Found!\n");
        exit(1);
      }else{
        List_remove(l, List_find(l, buffer));
        wallet = wallet + sell_item(buffer);
      }
    }else if(strcmp(ans, "7") == 0){
      printf("\nYour Wallet : %d\n", wallet);
      goto LOOP;
    }else if(strcmp(ans, "8") == 0){
      printf("\nYour diamond : %d\n", diamond);
      goto LOOP;
    }else if(strcmp(ans, "9") == 0){
      try += 1;
      srand(time(NULL));
      int r = rand() % 10;
      if(try <= 4){
        printf("You get %d diamond\n", r);
        diamond = diamond + r;
        goto LOOP;
      }
      printf("No diamond for you!\n");
      goto LOOP;
    }else if(strcmp(ans, "10") == 0){
      printf("Thankyou for visiting!");
      exit(0);
    }else{
      fprintf(stderr, "Bad Request!\n");
      exit(0);
    }
  }
}