/*	$NetBSD: bindresvport.c,v 1.25 2013/03/11 20:19:28 tron Exp $	*/

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char *sccsid = "@(#)bindresvport.c 1.8 88/02/08 SMI";
static char *sccsid = "@(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";
#else
__RCSID("$NetBSD: bindresvport.c,v 1.25 2013/03/11 20:19:28 tron Exp $");
#endif
#endif

/*
 * Copyright (c) 1987 by Sun Microsystems, Inc.
 */

#include "namespace.h"

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <errno.h>
#include <string.h>
#include <unistd.h>

#include <rpc/rpc.h>
#include "svc_fdset.h"

#ifdef __weak_alias
__weak_alias(bindresvport,_bindresvport)
__weak_alias(bindresvport_sa,_bindresvport_sa)
#endif

/*
 * Bind a socket to a privileged IP port
 */
int
bindresvport(int sd, struct sockaddr_in *brsin)
{
	return bindresvport_sa(sd, (struct sockaddr *)(void *)brsin);
}

/*
 * Bind a socket to a privileged IP port
 */
int
bindresvport_sa(int sd, struct sockaddr *sa)
{
	int error, old;
	struct sockaddr_storage myaddr;
	struct sockaddr_in *brsin;
#ifdef INET6
	struct sockaddr_in6 *brsin6;
#endif
	int proto, portrange, portlow;
	u_int16_t *portp;
	socklen_t salen;
	int af;

	if (sa == NULL) {
		salen = sizeof(myaddr);
		sa = (struct sockaddr *)(void *)&myaddr;

		if (getsockname(sd, sa, &salen) == -1)
			return -1;	/* errno is correctly set */

		af = sa->sa_family;
		memset(sa, 0, salen);
	} else
		af = sa->sa_family;

	switch (af) {
	case AF_INET:
		proto = IPPROTO_IP;
		portrange = IP_PORTRANGE;
		portlow = IP_PORTRANGE_LOW;
		brsin = (struct sockaddr_in *)(void *)sa;
		salen = sizeof(struct sockaddr_in);
		portp = &brsin->sin_port;
		break;
#ifdef INET6
	case AF_INET6:
		proto = IPPROTO_IPV6;
		portrange = IPV6_PORTRANGE;
		portlow = IPV6_PORTRANGE_LOW;
		brsin6 = (struct sockaddr_in6 *)(void *)sa;
		salen = sizeof(struct sockaddr_in6);
		portp = &brsin6->sin6_port;
		break;
#endif
	default:
		errno = EPFNOSUPPORT;
		return (-1);
	}
	sa->sa_family = af;
	sa->sa_len = salen;

	if (*portp == 0) {
		socklen_t oldlen = sizeof(old);

		error = getsockopt(sd, proto, portrange, &old, &oldlen);
		if (error < 0)
			return (error);
		error = setsockopt(sd, proto, portrange, &portlow,
		    (socklen_t)sizeof(portlow));
		if (error < 0)
			return (error);
	}

	error = bind(sd, sa, salen);

	if (*portp == 0) {
		int saved_errno = errno;

		if (error < 0) {
			if (setsockopt(sd, proto, portrange, &old,
			    (socklen_t)sizeof(old)) < 0)
				errno = saved_errno;
			return (error);
		}

		if (sa != (struct sockaddr *)(void *)&myaddr) {
			/* What did the kernel assign? */
			if (getsockname(sd, sa, &salen) < 0)
				errno = saved_errno;
			return (error);
		}
	}
	return (error);
}