rresvport.c revision 157016 
1/* $OpenBSD: rresvport.c,v 1.9 2005/11/10 10:00:17 espie Exp $ */
2/*
3 * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
4 * Copyright (c) 1983, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32/* OPENBSD ORIGINAL: lib/libc/net/rresvport.c */
33
34#include "includes.h"
35
36#ifndef HAVE_RRESVPORT_AF
37
38#if 0
39int
40rresvport(int *alport)
41{
42	return rresvport_af(alport, AF_INET);
43}
44#endif
45
46int
47rresvport_af(int *alport, sa_family_t af)
48{
49	struct sockaddr_storage ss;
50	struct sockaddr *sa;
51	u_int16_t *portp;
52	int s;
53	socklen_t salen;
54
55	memset(&ss, '\0', sizeof ss);
56	sa = (struct sockaddr *)&ss;
57
58	switch (af) {
59	case AF_INET:
60		salen = sizeof(struct sockaddr_in);
61		portp = &((struct sockaddr_in *)sa)->sin_port;
62		break;
63	case AF_INET6:
64		salen = sizeof(struct sockaddr_in6);
65		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
66		break;
67	default:
68		errno = EPFNOSUPPORT;
69		return (-1);
70	}
71	sa->sa_family = af;
72
73	s = socket(af, SOCK_STREAM, 0);
74	if (s < 0)
75		return (-1);
76
77	*portp = htons(*alport);
78	if (*alport < IPPORT_RESERVED - 1) {
79		if (bind(s, sa, salen) >= 0)
80			return (s);
81		if (errno != EADDRINUSE) {
82			(void)close(s);
83			return (-1);
84		}
85	}
86
87	*portp = 0;
88	sa->sa_family = af;
89	if (bindresvport_sa(s, sa) == -1) {
90		(void)close(s);
91		return (-1);
92	}
93	*alport = ntohs(*portp);
94	return (s);
95}
96
97#endif /* HAVE_RRESVPORT_AF */
98