bindresvport.c revision 1.19 
1/*	$NetBSD: bindresvport.c,v 1.19 2000/07/06 03:03:59 christos 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 1.19 2000/07/06 03:03:59 christos 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(sd, sin)
69	int sd;
70	struct sockaddr_in *sin;
71{
72	return bindresvport_sa(sd, (struct sockaddr *)(void *)sin);
73}
74
75/*
76 * Bind a socket to a privileged IP port
77 */
78int
79bindresvport_sa(sd, sa)
80	int sd;
81	struct sockaddr *sa;
82{
83	int error, old;
84	struct sockaddr_storage myaddr;
85	struct sockaddr_in *sin;
86#ifdef INET6
87	struct sockaddr_in6 *sin6;
88#endif
89	int proto, portrange, portlow;
90	u_int16_t *portp;
91	socklen_t salen;
92	int af;
93
94	if (sa == NULL) {
95		salen = sizeof(myaddr);
96		sa = (struct sockaddr *)(void *)&myaddr;
97
98		if (getsockname(sd, sa, &salen) == -1)
99			return -1;	/* errno is correctly set */
100
101		af = sa->sa_family;
102		memset(sa, 0, salen);
103	} else
104		af = sa->sa_family;
105
106	switch (af) {
107	case AF_INET:
108		proto = IPPROTO_IP;
109		portrange = IP_PORTRANGE;
110		portlow = IP_PORTRANGE_LOW;
111		sin = (struct sockaddr_in *)(void *)sa;
112		salen = sizeof(struct sockaddr_in);
113		portp = &sin->sin_port;
114		break;
115#ifdef INET6
116	case AF_INET6:
117		proto = IPPROTO_IPV6;
118		portrange = IPV6_PORTRANGE;
119		portlow = IPV6_PORTRANGE_LOW;
120		sin6 = (struct sockaddr_in6 *)(void *)sa;
121		salen = sizeof(struct sockaddr_in6);
122		portp = &sin6->sin6_port;
123		break;
124#endif
125	default:
126		errno = EPFNOSUPPORT;
127		return (-1);
128	}
129	sa->sa_family = af;
130	sa->sa_len = salen;
131
132	if (*portp == 0) {
133		socklen_t oldlen = sizeof(old);
134
135		error = getsockopt(sd, proto, portrange, &old, &oldlen);
136		if (error < 0)
137			return (error);
138		error = setsockopt(sd, proto, portrange, &portlow,
139		    sizeof(portlow));
140		if (error < 0)
141			return (error);
142	}
143
144	error = bind(sd, sa, salen);
145
146	if (*portp == 0) {
147		int saved_errno = errno;
148
149		if (error < 0) {
150			if (setsockopt(sd, proto, portrange, &old,
151			    sizeof(old)) < 0)
152				errno = saved_errno;
153			return (error);
154		}
155
156		if (sa != (struct sockaddr *)(void *)&myaddr) {
157			/* What did the kernel assign? */
158			if (getsockname(sd, sa, &salen) < 0)
159				errno = saved_errno;
160			return (error);
161		}
162	}
163	return (error);
164}
165