tcp_listen.c

linux下的tcp通信多线程示例,通过创建多线程来建立TCP联接.在嵌入式系统下运行

/* include tcp_listen */
//#include	"unp.h"
#include	"tcp_listen.h"
int
tcp_listen(const char *host, const char *serv, socklen_t *addrlenp)
{
	int				listenfd, n;
	const int		on = 1;
	struct addrinfo	hints, *res, *ressave;

	bzero(&hints, sizeof(struct addrinfo));
//	hints.ai_flags = AI_PASSIVE;
//	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;

	if ( (n = getaddrinfo(host, serv, &hints, &res)) != 0){
		printf("tcp_listen error for %s, %s: %s",
				 host, serv, gai_strerror(n));
	//	perror("tcp_listen error");
		exit(0);
	}
#if 0
	err_quit("tcp_listen error for %s, %s: %s",
				 host, serv, gai_strerror(n));
#endif
	ressave = res;

	do {
		listenfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
		if (listenfd < 0)
			continue;		/* error, try next one */

		setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
		if (bind(listenfd, res->ai_addr, res->ai_addrlen) == 0)
			break;			/* success */

		close(listenfd);	/* bind error, close and try next one */
	} while ( (res = res->ai_next) != NULL);

	if (res == NULL)	/* errno from final socket() or bind() */
		perror("tcp_listen error");
		//err_sys("tcp_listen error for %s, %s", host, serv);

	//listen(listenfd, LISTENQ);
	listen(listenfd, 16);

	if (addrlenp)
		*addrlenp = res->ai_addrlen;	/* return size of protocol address */

	freeaddrinfo(ressave);

	return(listenfd);
}
/* end tcp_listen */

/*
 * We place the wrapper function here, not in wraplib.c, because some
 * XTI programs need to include wraplib.c, and it also defines
 * a Tcp_listen() function.
 */

int
Tcp_listen(const char *host, const char *serv, socklen_t *addrlenp)
{
	return(tcp_listen(host, serv, addrlenp));
}