rresvport.c revision 126274 
1/* OPENBSD ORIGINAL: lib/libc/net/rresvport.c */
2
3/*
4 * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
5 * Copyright (c) 1983, 1993, 1994
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include "includes.h"
34
35#ifndef HAVE_RRESVPORT_AF
36
37#if defined(LIBC_SCCS) && !defined(lint)
38static char *rcsid = "$OpenBSD: rresvport.c,v 1.6 2003/06/03 02:11:35 deraadt Exp $";
39#endif /* LIBC_SCCS and not lint */
40
41#include "includes.h"
42
43#if 0
44int
45rresvport(alport)
46	int *alport;
47{
48	return rresvport_af(alport, AF_INET);
49}
50#endif
51
52int
53rresvport_af(int *alport, sa_family_t af)
54{
55	struct sockaddr_storage ss;
56	struct sockaddr *sa;
57	u_int16_t *portp;
58	int s;
59	socklen_t salen;
60
61	memset(&ss, '\0', sizeof ss);
62	sa = (struct sockaddr *)&ss;
63
64	switch (af) {
65	case AF_INET:
66		salen = sizeof(struct sockaddr_in);
67		portp = &((struct sockaddr_in *)sa)->sin_port;
68		break;
69	case AF_INET6:
70		salen = sizeof(struct sockaddr_in6);
71		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
72		break;
73	default:
74		errno = EPFNOSUPPORT;
75		return (-1);
76	}
77	sa->sa_family = af;
78
79	s = socket(af, SOCK_STREAM, 0);
80	if (s < 0)
81		return (-1);
82
83	*portp = htons(*alport);
84	if (*alport < IPPORT_RESERVED - 1) {
85		if (bind(s, sa, salen) >= 0)
86			return (s);
87		if (errno != EADDRINUSE) {
88			(void)close(s);
89			return (-1);
90		}
91	}
92
93	*portp = 0;
94	sa->sa_family = af;
95	if (bindresvport_sa(s, sa) == -1) {
96		(void)close(s);
97		return (-1);
98	}
99	*alport = ntohs(*portp);
100	return (s);
101}
102
103#endif /* HAVE_RRESVPORT_AF */
104