#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <string.h>

/* ./udp remote port local port interval */

int main(int ac, char ** av)
{
	int port=8888;
	int port2=port;
	char * host;
	char * data="data";
	int sk,rv;
	struct sockaddr_in addr;
	struct sockaddr_in laddr;
	int interval=0;
	
	if (ac < 2) {
		return 1;
	}
	if (ac >= 3) {
		port=atoi(av[2]);
		port2=port;
	}
	if (ac >= 4) {
		port2=atoi(av[3]);
		if (port2 == 0) {
			port2=port;
		}
	}
	if (ac >= 5) {
		interval=atoi(av[4]);
	}
	addr.sin_family=PF_INET;
	addr.sin_addr.s_addr=inet_addr(av[1]);
	addr.sin_port=htons(port);
	printf("Dst: %s:%d\n", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
	sk=socket(PF_INET, SOCK_DGRAM, 0);
	assert(sk >= 0);
	laddr.sin_family=PF_INET;
	laddr.sin_port=htons(port2);
	laddr.sin_addr.s_addr=inet_addr("0.0.0.0");
	rv=bind(sk, (struct sockaddr *) &laddr, sizeof(struct sockaddr_in));
	printf("bind: rv=%d  errno=%d  strerrno=%s\n", rv, errno, strerror(errno));
	rv=sendto(sk, data, strlen(data)+1, 0, (struct sockaddr *) &addr, sizeof(struct sockaddr_in));
	printf("sendto: rv=%d  errno=%d  strerrno=%s\n", rv, errno, strerror(errno));
	if (interval > 0) {
		do {
			sleep(interval);
			rv=sendto(sk, data, strlen(data)+1, 0, (struct sockaddr *) &addr, sizeof(struct sockaddr_in));
			printf("sendto: rv=%d  errno=%d  strerrno=%s\n", rv, errno, strerror(errno));
		} while (1);
	}
}