bindresvport.c revision 1.24 
1/*	$NetBSD: bindresvport.c,v 1.24 2013/03/05 19:55:22 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 1.24 2013/03/05 19:55:22 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#include "svc_fdset.h"
59
60#ifdef __weak_alias
61__weak_alias(bindresvport,_bindresvport)
62__weak_alias(bindresvport_sa,_bindresvport_sa)
63#endif
64
65/*
66 * Bind a socket to a privileged IP port
67 */
68int
69bindresvport(int sd, struct sockaddr_in *brsin)
70{
71	return bindresvport_sa(sd, (struct sockaddr *)(void *)brsin);
72}
73
74/*
75 * Bind a socket to a privileged IP port
76 */
77int
78bindresvport_sa(int sd, struct sockaddr *sa)
79{
80	int error, old;
81	struct sockaddr_storage myaddr;
82	struct sockaddr_in *brsin;
83#ifdef INET6
84	struct sockaddr_in6 *brsin6;
85#endif
86	int proto, portrange, portlow;
87	u_int16_t *portp;
88	socklen_t salen;
89	int af;
90
91	if (sa == NULL) {
92		salen = sizeof(myaddr);
93		sa = (struct sockaddr *)(void *)&myaddr;
94
95		if (getsockname(sd, sa, &salen) == -1)
96			return -1;	/* errno is correctly set */
97
98		af = sa->sa_family;
99		memset(sa, 0, salen);
100	} else
101		af = sa->sa_family;
102
103	switch (af) {
104	case AF_INET:
105		proto = IPPROTO_IP;
106		portrange = IP_PORTRANGE;
107		portlow = IP_PORTRANGE_LOW;
108		brsin = (struct sockaddr_in *)(void *)sa;
109		salen = sizeof(struct sockaddr_in);
110		portp = &brsin->sin_port;
111		break;
112#ifdef INET6
113	case AF_INET6:
114		proto = IPPROTO_IPV6;
115		portrange = IPV6_PORTRANGE;
116		portlow = IPV6_PORTRANGE_LOW;
117		brsin6 = (struct sockaddr_in6 *)(void *)sa;
118		salen = sizeof(struct sockaddr_in6);
119		portp = &brsin6->sin6_port;
120		break;
121#endif
122	default:
123		errno = EPFNOSUPPORT;
124		return (-1);
125	}
126	sa->sa_family = af;
127	sa->sa_len = salen;
128
129	if (*portp == 0) {
130		socklen_t oldlen = sizeof(old);
131
132		error = getsockopt(sd, proto, portrange, &old, &oldlen);
133		if (error < 0)
134			return (error);
135		error = setsockopt(sd, proto, portrange, &portlow,
136		    (socklen_t)sizeof(portlow));
137		if (error < 0)
138			return (error);
139	}
140
141	error = bind(sd, sa, salen);
142
143	if (*portp == 0) {
144		int saved_errno = errno;
145
146		if (error < 0) {
147			if (setsockopt(sd, proto, portrange, &old,
148			    (socklen_t)sizeof(old)) < 0)
149				errno = saved_errno;
150			return (error);
151		}
152
153		if (sa != (struct sockaddr *)(void *)&myaddr) {
154			/* What did the kernel assign? */
155			if (getsockname(sd, sa, &salen) < 0)
156				errno = saved_errno;
157			return (error);
158		}
159	}
160	return (error);
161}
162