sock_bind_wild.c

unix网络编程卷1：套接口API的全书源码

#include	"unp.h"

int
sock_bind_wild(int sockfd, int family)
{
	socklen_t	len;

	switch (family) {
	case AF_INET: {
		struct sockaddr_in	sin;

		bzero(&sin, sizeof(sin));
		sin.sin_family = AF_INET;
		sin.sin_addr.s_addr = htonl(INADDR_ANY);
		sin.sin_port = htons(0);	/* bind ephemeral port */

		if (bind(sockfd, (SA *) &sin, sizeof(sin)) < 0)
			return(-1);
		len = sizeof(sin);
		if (getsockname(sockfd, (SA *) &sin, &len) < 0)
			return(-1);
		return(sin.sin_port);
	}

#ifdef	IPV6
	case AF_INET6: {
		struct sockaddr_in6	sin6;

		bzero(&sin6, sizeof(sin6));
		sin6.sin6_family = AF_INET6;
		sin6.sin6_addr = in6addr_any;
		sin6.sin6_port = htons(0);	/* bind ephemeral port */

		if (bind(sockfd, (SA *) &sin6, sizeof(sin6)) < 0)
			return(-1);
		len = sizeof(sin6);
		if (getsockname(sockfd, (SA *) &sin6, &len) < 0)
			return(-1);
		return(sin6.sin6_port);
	}
#endif
	}
	return(-1);
}

int
Sock_bind_wild(int sockfd, int family)
{
	int		port;

	if ( (port = sock_bind_wild(sockfd, family)) < 0)
		err_sys("sock_bind_wild error");

	return(port);
}