rresvport.c revision 181097 
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#include <sys/types.h>
39#include <sys/socket.h>
40
41#include <netinet/in.h>
42#include <arpa/inet.h>
43
44#include <errno.h>
45#include <stdlib.h>
46#include <string.h>
47
48#if 0
49int
50rresvport(int *alport)
51{
52	return rresvport_af(alport, AF_INET);
53}
54#endif
55
56int
57rresvport_af(int *alport, sa_family_t af)
58{
59	struct sockaddr_storage ss;
60	struct sockaddr *sa;
61	u_int16_t *portp;
62	int s;
63	socklen_t salen;
64
65	memset(&ss, '\0', sizeof ss);
66	sa = (struct sockaddr *)&ss;
67
68	switch (af) {
69	case AF_INET:
70		salen = sizeof(struct sockaddr_in);
71		portp = &((struct sockaddr_in *)sa)->sin_port;
72		break;
73	case AF_INET6:
74		salen = sizeof(struct sockaddr_in6);
75		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
76		break;
77	default:
78		errno = EPFNOSUPPORT;
79		return (-1);
80	}
81	sa->sa_family = af;
82
83	s = socket(af, SOCK_STREAM, 0);
84	if (s < 0)
85		return (-1);
86
87	*portp = htons(*alport);
88	if (*alport < IPPORT_RESERVED - 1) {
89		if (bind(s, sa, salen) >= 0)
90			return (s);
91		if (errno != EADDRINUSE) {
92			(void)close(s);
93			return (-1);
94		}
95	}
96
97	*portp = 0;
98	sa->sa_family = af;
99	if (bindresvport_sa(s, sa) == -1) {
100		(void)close(s);
101		return (-1);
102	}
103	*alport = ntohs(*portp);
104	return (s);
105}
106
107#endif /* HAVE_RRESVPORT_AF */
108