#define _XOPEN_SOURCE   500
#define __EXTENSIONS__

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/signal.h>
#include <sys/socket.h>
#include <sys/filio.h>
#include <netinet/sctp.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>



#define MAXIDLETIME     1

#define   BUFLEN  1024


static void
print_src(int fd, sctp_assoc_t assoc_id)
{
        struct sctp_status sstat;
        struct sctp_paddrinfo *spinfo;
        char tmpname[INET_ADDRSTRLEN];
        unsigned int port;
        unsigned int ulen;
        struct sockaddr_in *s_in;

        bzero(&sstat, sizeof (sstat));

        ulen = sizeof (sstat);
        if (sctp_opt_info(fd, assoc_id, SCTP_STATUS, &sstat, &ulen) < 0) {
                perror("sctp_opt_info()");
                return;
        }
        spinfo = &sstat.sstat_primary;

        s_in = (struct sockaddr_in *)&spinfo->spinfo_address;
        inet_ntop(AF_INET, &s_in->sin_addr, tmpname, sizeof (tmpname));
        port = ntohs(s_in->sin_port);
        printf("Msg from %d: %s/%d\n", assoc_id, tmpname, port);
}

int echo_s;
struct sockaddr_in laddr;

int
main(int argc, char **argv)
{
	struct sockaddr_in toaddr;
	struct sctp_event_subscribe ses;
	int ret; 
        int i;
	struct msghdr In_mhdr;
	struct msghdr Out_mhdr;
	struct iovec iov;
	char data[BUFLEN];
	char cdata[sizeof (struct sctp_sndrcvinfo) + sizeof (struct cmsghdr)];
	struct cmsghdr *cmsg;
	struct sctp_sndrcvinfo *sinfo;
	struct sctp_assoc_change *sac;
	struct sockaddr_in from;
	socklen_t fromlen = sizeof (struct sockaddr_in);
	socklen_t tolen = sizeof (struct sockaddr_in);
	fd_set	rset;
	struct hostent *hp;
	int error;
        int lport, rport;


        if (argc < 4) {
		printf("usage: sctp_client <local_port> <remote_host> <remote_port>\n");
                exit(0);
        }
	lport = atoi(argv[1]);
	rport = atoi(argv[3]);

	bzero(&laddr, sizeof (laddr));
	laddr.sin_family = AF_INET;
	laddr.sin_addr.s_addr = INADDR_ANY;
	laddr.sin_port = htons(lport);

	CreateSocket();

/*
	i = 1;
	setsockopt(echo_s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof (i));
	i = MAXIDLETIME;
	setsockopt(echo_s, IPPROTO_SCTP, SCTP_AUTOCLOSE, &i, sizeof (i));
*/

	bzero(&toaddr, sizeof (toaddr));
	hp = getipnodebyname(argv[2], AF_INET, AI_DEFAULT, &error);
	if (hp == NULL) {
		fprintf(stderr, "host not found\n");
		exit(1);
	}
	toaddr.sin_family = AF_INET;
	toaddr.sin_addr.s_addr = *(ipaddr_t *)hp->h_addr_list[0];
	toaddr.sin_port = htons(rport);

	bzero(&ses, sizeof (ses));
	ses.sctp_data_io_event = 1;
	setsockopt(echo_s, IPPROTO_SCTP, SCTP_EVENTS, &ses, sizeof (ses));

	FD_ZERO(&rset);

	while (1) {

		FD_SET(echo_s, &rset);
		FD_SET(0, &rset);
		select(5, &rset, NULL, NULL, NULL);
		if (FD_ISSET (echo_s, &rset)) {
			bzero(cdata, sizeof (cdata));
			bzero(&In_mhdr, sizeof (In_mhdr));
			In_mhdr.msg_name = &from;
			In_mhdr.msg_namelen = fromlen;
			In_mhdr.msg_iov = &iov;
			In_mhdr.msg_iovlen = 1;
			In_mhdr.msg_control = cdata;
			In_mhdr.msg_controllen = sizeof (cdata);
			iov.iov_base = data;
			iov.iov_len = sizeof (data);
			cmsg = (struct cmsghdr *)cdata;
			sinfo = (struct sctp_sndrcvinfo *)(cmsg + 1);

			if ((ret = recvmsg(echo_s, &In_mhdr, MSG_DONTWAIT)) < 0) {
				perror("recvmsg()");
			}
			if (In_mhdr.msg_controllen) {
				print_src(echo_s, sinfo->sinfo_assoc_id);
			}
                        printf("got back: "); fflush (stdout);
			write(1, data, ret);

		}
		if (FD_ISSET (0, &rset)) {
			bzero(cdata, sizeof (cdata));
			bzero(&Out_mhdr, sizeof (Out_mhdr));
			Out_mhdr.msg_name = &toaddr;
			Out_mhdr.msg_namelen = tolen;
			Out_mhdr.msg_iov = &iov;
			Out_mhdr.msg_iovlen = 1;
			Out_mhdr.msg_control = cdata;
			Out_mhdr.msg_controllen = sizeof (cdata);
			iov.iov_base = data;
			iov.iov_len = sizeof (data);
			cmsg = (struct cmsghdr *)cdata;
			sinfo = (struct sctp_sndrcvinfo *)(cmsg + 1);

			ret = read(0, data, BUFLEN);
                        printf("data input: "); fflush(stdout);
                        write (1, data, ret);
			iov.iov_len = ret;
			if (sendmsg(echo_s, &Out_mhdr, MSG_DONTWAIT) < 0) {
				perror("sendmsg()");
			}
		}
	}
}
CreateSocket()
{

	echo_s = socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP);
	if (bind(echo_s, (struct sockaddr *)&laddr, sizeof (laddr)) < 0) {
		perror("bind(ECHO_PORT)");
		exit(1);
	}
}