#include<stdio.h>
#include<unistd.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<fcntl.h>

int main(int argc, char ** argv){
	if(argc < 2){
		printf("Usage:  %s ip_to_block\n", argv[0]);
		return 1;
	}

	struct in_addr block_address;
	if(!inet_aton(argv[1], &block_address)){
		printf("Could not interpret %s as an IP address\n", argv[1]);
		return 1;
	}

	int fd = open("/proc/blockaddr", O_WRONLY);
	if(fd < 0){
		perror("open");
		return 1;
	}
	
	write(fd, &block_address, 4);
	close(fd);
	return 0;
}