#include <stdio.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/fcntl.h>
#include <netinet/in.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <unistd.h>
#include <errno.h>

main(int argc,char ** argv)
{

	struct sockaddr_un sockaddr;
	char line[128];
	char reply[128];
	int socket_errno;
	int i, err, n;
	int s;
	int ret;
	int	fd[2];
	struct 	cmsghdr *cmsg;
	int 	*fdptr;
	char 	cmsgbuf[CMSG_SPACE(sizeof (int))];
	struct iovec vec;
	struct msghdr msghdr;

	if ( socketpair( AF_UNIX, SOCK_STREAM, 0, fd ) == -1 ) {
		fprintf(stderr, "socketpait error\n");
	}
	close(fd[1]);

	n = 0;
	while (1) {
		if ((s=socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
			socket_errno = errno;
			fprintf(stderr,"can't create socket [%d]\n",socket_errno);
			exit(-1);
		}

		memset(&sockaddr, '\0', sizeof(sockaddr));
		sockaddr.sun_family      = AF_UNIX;
		strcpy(sockaddr.sun_path, "/tmp/unix_d_test");
		
		if (connect(s,(struct sockaddr *)&sockaddr,sizeof(sockaddr)) == -1) {
			socket_errno = errno;
			fprintf(stderr,"connect error [%d]\n",errno);
			exit(-1);
		}
		
		for(i = 0 ; i < 128 ; i++) {
			line[i] = 0;
		}
		sprintf(line, "[%d]:client pid is %d", n, getpid());
		
		vec.iov_base = line;
		vec.iov_len  = 128;
		
		msghdr.msg_name       = NULL;
		msghdr.msg_namelen    = 0;
		msghdr.msg_iov        = &vec;
		msghdr.msg_iovlen     = 1;
		msghdr.msg_flags = 0;
		
		msghdr.msg_control = cmsgbuf;
		msghdr.msg_controllen = sizeof cmsgbuf;
		cmsg = CMSG_FIRSTHDR(&msghdr);
		cmsg->cmsg_len   = CMSG_LEN(sizeof(int) * 1);
		cmsg->cmsg_level = SOL_SOCKET;
		cmsg->cmsg_type  = SCM_RIGHTS;
		fdptr = (int *)CMSG_DATA(cmsg);
		memcpy(fdptr, fd, sizeof(int) * 1);
		msghdr.msg_controllen = cmsg->cmsg_len;
		
		if ((ret = sendmsg(s, &msghdr, 0 )) < 128) {
			fprintf(stderr, "sendmsg error %d\n", errno);
			exit(-1);
		}
		fprintf(stderr, "[%d]:sendmsg() %d byte OK. fd:%d\n", n, ret, fd[0]);
		
		vec.iov_base = reply;
		vec.iov_len  = 128;
		
		msghdr.msg_name       = NULL;
		msghdr.msg_namelen    = 0;
		msghdr.msg_iov        = &vec;
		msghdr.msg_iovlen     = 1;
		msghdr.msg_flags = 0;
		msghdr.msg_controllen = 0;
		msghdr.msg_control    = NULL;
		
		if ((ret = recvmsg(s, &msghdr, 0)) < 128) {
			fprintf(stderr, "recvmsg() error %d\n", errno);
			exit(-1);
		}
		fprintf(stderr, "recvmgs() %d byte OK.\n", ret);

		close(s);
		n++;
	}
	
	fprintf(stderr,"GOOD BY \n");
	exit (0);
}