rresvport.c revision 106121 
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. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by the University of
17 *	California, Berkeley and its contributors.
18 *	This product includes software developed by Theo de Raadt.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "includes.h"
37
38#ifndef HAVE_RRESVPORT_AF
39
40#if defined(LIBC_SCCS) && !defined(lint)
41static char *rcsid = "$OpenBSD: rresvport.c,v 1.5 2000/01/26 03:43:20 deraadt Exp $";
42#endif /* LIBC_SCCS and not lint */
43
44#include "includes.h"
45
46#if 0
47int
48rresvport(alport)
49	int *alport;
50{
51	return rresvport_af(alport, AF_INET);
52}
53#endif
54
55int
56rresvport_af(int *alport, sa_family_t af)
57{
58	struct sockaddr_storage ss;
59	struct sockaddr *sa;
60	u_int16_t *portp;
61	int s;
62	socklen_t salen;
63
64	memset(&ss, '\0', sizeof ss);
65	sa = (struct sockaddr *)&ss;
66
67	switch (af) {
68	case AF_INET:
69		salen = sizeof(struct sockaddr_in);
70		portp = &((struct sockaddr_in *)sa)->sin_port;
71		break;
72	case AF_INET6:
73		salen = sizeof(struct sockaddr_in6);
74		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
75		break;
76	default:
77		errno = EPFNOSUPPORT;
78		return (-1);
79	}
80	sa->sa_family = af;
81
82	s = socket(af, SOCK_STREAM, 0);
83	if (s < 0)
84		return (-1);
85
86	*portp = htons(*alport);
87	if (*alport < IPPORT_RESERVED - 1) {
88		if (bind(s, sa, salen) >= 0)
89			return (s);
90		if (errno != EADDRINUSE) {
91			(void)close(s);
92			return (-1);
93		}
94	}
95
96	*portp = 0;
97	sa->sa_family = af;
98	if (bindresvport_sa(s, sa) == -1) {
99		(void)close(s);
100		return (-1);
101	}
102	*alport = ntohs(*portp);
103	return (s);
104}
105
106#endif /* HAVE_RRESVPORT_AF */
107