rresvport.c revision 124208 
1/*
2 * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
3 * Copyright (c) 1983, 1993, 1994
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include "includes.h"
32
33#ifndef HAVE_RRESVPORT_AF
34
35#if defined(LIBC_SCCS) && !defined(lint)
36static char *rcsid = "$OpenBSD: rresvport.c,v 1.6 2003/06/03 02:11:35 deraadt Exp $";
37#endif /* LIBC_SCCS and not lint */
38
39#include "includes.h"
40
41#if 0
42int
43rresvport(alport)
44	int *alport;
45{
46	return rresvport_af(alport, AF_INET);
47}
48#endif
49
50int
51rresvport_af(int *alport, sa_family_t af)
52{
53	struct sockaddr_storage ss;
54	struct sockaddr *sa;
55	u_int16_t *portp;
56	int s;
57	socklen_t salen;
58
59	memset(&ss, '\0', sizeof ss);
60	sa = (struct sockaddr *)&ss;
61
62	switch (af) {
63	case AF_INET:
64		salen = sizeof(struct sockaddr_in);
65		portp = &((struct sockaddr_in *)sa)->sin_port;
66		break;
67	case AF_INET6:
68		salen = sizeof(struct sockaddr_in6);
69		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
70		break;
71	default:
72		errno = EPFNOSUPPORT;
73		return (-1);
74	}
75	sa->sa_family = af;
76
77	s = socket(af, SOCK_STREAM, 0);
78	if (s < 0)
79		return (-1);
80
81	*portp = htons(*alport);
82	if (*alport < IPPORT_RESERVED - 1) {
83		if (bind(s, sa, salen) >= 0)
84			return (s);
85		if (errno != EADDRINUSE) {
86			(void)close(s);
87			return (-1);
88		}
89	}
90
91	*portp = 0;
92	sa->sa_family = af;
93	if (bindresvport_sa(s, sa) == -1) {
94		(void)close(s);
95		return (-1);
96	}
97	*alport = ntohs(*portp);
98	return (s);
99}
100
101#endif /* HAVE_RRESVPORT_AF */
102