bindresvport.c revision 1.23 
1/*	$NetBSD: bindresvport.c,v 1.23 2012/03/20 17:14:50 matt Exp $	*/
2
3/*
4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5 * unrestricted use provided that this legend is included on all tape
6 * media and as a part of the software program in whole or part.  Users
7 * may copy or modify Sun RPC without charge, but are not authorized
8 * to license or distribute it to anyone else except as part of a product or
9 * program developed by the user.
10 *
11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14 *
15 * Sun RPC is provided with no support and without any obligation on the
16 * part of Sun Microsystems, Inc. to assist in its use, correction,
17 * modification or enhancement.
18 *
19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21 * OR ANY PART THEREOF.
22 *
23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24 * or profits or other special, indirect and consequential damages, even if
25 * Sun has been advised of the possibility of such damages.
26 *
27 * Sun Microsystems, Inc.
28 * 2550 Garcia Avenue
29 * Mountain View, California  94043
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char *sccsid = "@(#)bindresvport.c 1.8 88/02/08 SMI";
36static char *sccsid = "@(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";
37#else
38__RCSID("$NetBSD: bindresvport.c,v 1.23 2012/03/20 17:14:50 matt Exp $");
39#endif
40#endif
41
42/*
43 * Copyright (c) 1987 by Sun Microsystems, Inc.
44 */
45
46#include "namespace.h"
47
48#include <sys/types.h>
49#include <sys/socket.h>
50
51#include <netinet/in.h>
52
53#include <errno.h>
54#include <string.h>
55#include <unistd.h>
56
57#include <rpc/rpc.h>
58
59#ifdef __weak_alias
60__weak_alias(bindresvport,_bindresvport)
61__weak_alias(bindresvport_sa,_bindresvport_sa)
62#endif
63
64/*
65 * Bind a socket to a privileged IP port
66 */
67int
68bindresvport(int sd, struct sockaddr_in *brsin)
69{
70	return bindresvport_sa(sd, (struct sockaddr *)(void *)brsin);
71}
72
73/*
74 * Bind a socket to a privileged IP port
75 */
76int
77bindresvport_sa(int sd, struct sockaddr *sa)
78{
79	int error, old;
80	struct sockaddr_storage myaddr;
81	struct sockaddr_in *brsin;
82#ifdef INET6
83	struct sockaddr_in6 *brsin6;
84#endif
85	int proto, portrange, portlow;
86	u_int16_t *portp;
87	socklen_t salen;
88	int af;
89
90	if (sa == NULL) {
91		salen = sizeof(myaddr);
92		sa = (struct sockaddr *)(void *)&myaddr;
93
94		if (getsockname(sd, sa, &salen) == -1)
95			return -1;	/* errno is correctly set */
96
97		af = sa->sa_family;
98		memset(sa, 0, salen);
99	} else
100		af = sa->sa_family;
101
102	switch (af) {
103	case AF_INET:
104		proto = IPPROTO_IP;
105		portrange = IP_PORTRANGE;
106		portlow = IP_PORTRANGE_LOW;
107		brsin = (struct sockaddr_in *)(void *)sa;
108		salen = sizeof(struct sockaddr_in);
109		portp = &brsin->sin_port;
110		break;
111#ifdef INET6
112	case AF_INET6:
113		proto = IPPROTO_IPV6;
114		portrange = IPV6_PORTRANGE;
115		portlow = IPV6_PORTRANGE_LOW;
116		brsin6 = (struct sockaddr_in6 *)(void *)sa;
117		salen = sizeof(struct sockaddr_in6);
118		portp = &brsin6->sin6_port;
119		break;
120#endif
121	default:
122		errno = EPFNOSUPPORT;
123		return (-1);
124	}
125	sa->sa_family = af;
126	sa->sa_len = salen;
127
128	if (*portp == 0) {
129		socklen_t oldlen = sizeof(old);
130
131		error = getsockopt(sd, proto, portrange, &old, &oldlen);
132		if (error < 0)
133			return (error);
134		error = setsockopt(sd, proto, portrange, &portlow,
135		    (socklen_t)sizeof(portlow));
136		if (error < 0)
137			return (error);
138	}
139
140	error = bind(sd, sa, salen);
141
142	if (*portp == 0) {
143		int saved_errno = errno;
144
145		if (error < 0) {
146			if (setsockopt(sd, proto, portrange, &old,
147			    (socklen_t)sizeof(old)) < 0)
148				errno = saved_errno;
149			return (error);
150		}
151
152		if (sa != (struct sockaddr *)(void *)&myaddr) {
153			/* What did the kernel assign? */
154			if (getsockname(sd, sa, &salen) < 0)
155				errno = saved_errno;
156			return (error);
157		}
158	}
159	return (error);
160}
161