hacking-the-art-of-exploitation

printf("6 - Reset your account at 100 credits\n");
printf("7 - Quit\n");
printf("[Name: %s]\n", player.name);
printf("[You have %u credits] -> ", player.credits);
scanf("%d", &choice);
}
if((choice < 1) || (choice > 7))
printf("\n[!!] The number %d is an invalid selection.\n\n", choice);
else if (choice < 4) {
// Otherwise, choice was a game of some sort.
if(choice != last_game) { // If the function ptr isn't set
if(choice == 1) // then point it at the selected game
player.current_game = pick_a_number;
else if(choice == 2)
player.current_game = dealer_no_match;
else
player.current_game = find_the_ace;
last_game = choice; // and set last_game.
}
play_the_game();
// Play the game.
}
else if (choice == 4)
show_highscore();
else if (choice == 5) {
printf("\nChange user name\n");
printf("Enter your new name: ");
input_name();
printf("Your name has been changed.\n\n");
}
else if (choice == 6) {
printf("\nYour account has been reset with 100 credits.\n\n");
player.credits = 100;
}
}
update_player_data();
printf("\nThanks for playing! Bye.\n");
// This function reads the player data for the current uid
// from the file. It returns -1 if it is unable to find player
// data for the current uid.
int get_player_data() {
int fd, uid, read_bytes;
struct user entry;
uid = getuid();
fd = open(DATAFILE, O_RDONLY);
if(fd == -1) // Can't open the file, maybe it doesn't exist
return -1;
read_bytes = read(fd, &entry, sizeof(struct user)); // Read the first chunk.
while(entry.uid != uid && read_bytes > 0) { // Loop until proper uid is found.
read_bytes = read(fd, &entry, sizeof(struct user)); // Keep reading.
}
close(fd); // Close the file.
if(read_bytes < sizeof(struct user)) // This means that the end of file was reached.
104 0x200