bindresvport.c revision 331722 
1/*	$NetBSD: bindresvport.c,v 1.19 2000/07/06 03:03:59 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * 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 are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 *   this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 *   this list of conditions and the following disclaimer in the documentation
13 *   and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 *   contributors may be used to endorse or promote products derived
16 *   from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND 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 COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#if defined(LIBC_SCCS) && !defined(lint)
32static char *sccsid2 = "from: @(#)bindresvport.c 1.8 88/02/08 SMI";
33static char *sccsid = "from: @(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";
34#endif
35/* from: $OpenBSD: bindresvport.c,v 1.7 1996/07/30 16:25:47 downsj Exp $ */
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD: stable/11/lib/libc/rpc/bindresvport.c 331722 2018-03-29 02:50:57Z eadler $");
38
39/*
40 * Copyright (c) 1987 by Sun Microsystems, Inc.
41 *
42 * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
43 */
44
45#include "namespace.h"
46#include <sys/types.h>
47#include <sys/socket.h>
48
49#include <netinet/in.h>
50
51#include <errno.h>
52#include <string.h>
53#include <unistd.h>
54
55#include <rpc/rpc.h>
56
57#include <string.h>
58#include "un-namespace.h"
59
60/*
61 * Bind a socket to a privileged IP port
62 */
63int
64bindresvport(int sd, struct sockaddr_in *sin)
65{
66	return bindresvport_sa(sd, (struct sockaddr *)sin);
67}
68
69/*
70 * Bind a socket to a privileged IP port
71 */
72int
73bindresvport_sa(int sd, struct sockaddr *sa)
74{
75	int old, error, af;
76	struct sockaddr_storage myaddr;
77	struct sockaddr_in *sin;
78#ifdef INET6
79	struct sockaddr_in6 *sin6;
80#endif
81	int proto, portrange, portlow;
82	u_int16_t *portp;
83	socklen_t salen;
84
85	if (sa == NULL) {
86		salen = sizeof(myaddr);
87		sa = (struct sockaddr *)&myaddr;
88
89		if (_getsockname(sd, sa, &salen) == -1)
90			return -1;	/* errno is correctly set */
91
92		af = sa->sa_family;
93		memset(sa, 0, salen);
94	} else
95		af = sa->sa_family;
96
97	switch (af) {
98	case AF_INET:
99		proto = IPPROTO_IP;
100		portrange = IP_PORTRANGE;
101		portlow = IP_PORTRANGE_LOW;
102		sin = (struct sockaddr_in *)sa;
103		salen = sizeof(struct sockaddr_in);
104		portp = &sin->sin_port;
105		break;
106#ifdef INET6
107	case AF_INET6:
108		proto = IPPROTO_IPV6;
109		portrange = IPV6_PORTRANGE;
110		portlow = IPV6_PORTRANGE_LOW;
111		sin6 = (struct sockaddr_in6 *)sa;
112		salen = sizeof(struct sockaddr_in6);
113		portp = &sin6->sin6_port;
114		break;
115#endif
116	default:
117		errno = EPFNOSUPPORT;
118		return (-1);
119	}
120	sa->sa_family = af;
121	sa->sa_len = salen;
122
123	if (*portp == 0) {
124		socklen_t oldlen = sizeof(old);
125
126		error = _getsockopt(sd, proto, portrange, &old, &oldlen);
127		if (error < 0)
128			return (error);
129
130		error = _setsockopt(sd, proto, portrange, &portlow,
131		    sizeof(portlow));
132		if (error < 0)
133			return (error);
134	}
135
136	error = _bind(sd, sa, salen);
137
138	if (*portp == 0) {
139		int saved_errno = errno;
140
141		if (error < 0) {
142			if (_setsockopt(sd, proto, portrange, &old,
143			    sizeof(old)) < 0)
144				errno = saved_errno;
145			return (error);
146		}
147
148		if (sa != (struct sockaddr *)&myaddr) {
149			/* Hmm, what did the kernel assign? */
150			if (_getsockname(sd, sa, &salen) < 0)
151				errno = saved_errno;
152			return (error);
153		}
154	}
155	return (error);
156}
157