/*      $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);
}