bindresvport.c revision 98937 
1/* This file has be modified from the original OpenBSD source */
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 "config.h"
33
34#ifndef HAVE_BINDRESVPORT_SA
35
36#if defined(LIBC_SCCS) && !defined(lint)
37static char *rcsid = "$OpenBSD: bindresvport.c,v 1.13 2000/01/26 03:43:21 deraadt Exp $";
38#endif /* LIBC_SCCS and not lint */
39
40/*
41 * Copyright (c) 1987 by Sun Microsystems, Inc.
42 *
43 * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
44 */
45
46#include "includes.h"
47
48#define STARTPORT 600
49#define ENDPORT (IPPORT_RESERVED - 1)
50#define NPORTS	(ENDPORT - STARTPORT + 1)
51
52/*
53 * Bind a socket to a privileged IP port
54 */
55int
56bindresvport_sa(sd, sa)
57	int sd;
58	struct sockaddr *sa;
59{
60	int error, af;
61	struct sockaddr_storage myaddr;
62	struct sockaddr_in *sin;
63	struct sockaddr_in6 *sin6;
64	u_int16_t *portp;
65	u_int16_t port;
66	socklen_t salen;
67	int i;
68
69	if (sa == NULL) {
70		memset(&myaddr, 0, sizeof(myaddr));
71		sa = (struct sockaddr *)&myaddr;
72
73		if (getsockname(sd, sa, &salen) == -1)
74			return -1;	/* errno is correctly set */
75
76		af = sa->sa_family;
77		memset(&myaddr, 0, salen);
78	} else
79		af = sa->sa_family;
80
81	if (af == AF_INET) {
82		sin = (struct sockaddr_in *)sa;
83		salen = sizeof(struct sockaddr_in);
84		portp = &sin->sin_port;
85	} else if (af == AF_INET6) {
86		sin6 = (struct sockaddr_in6 *)sa;
87		salen = sizeof(struct sockaddr_in6);
88		portp = &sin6->sin6_port;
89	} else {
90		errno = EPFNOSUPPORT;
91		return (-1);
92	}
93	sa->sa_family = af;
94
95	port = ntohs(*portp);
96	if (port == 0)
97		port = (arc4random() % NPORTS) + STARTPORT;
98
99	/* Avoid warning */
100	error = -1;
101
102	for(i = 0; i < NPORTS; i++) {
103		*portp = htons(port);
104
105		error = bind(sd, sa, salen);
106
107		/* Terminate on success */
108		if (error == 0)
109			break;
110
111		/* Terminate on errors, except "address already in use" */
112		if ((error < 0) && !((errno == EADDRINUSE) || (errno == EINVAL)))
113			break;
114
115		port++;
116		if (port > ENDPORT)
117			port = STARTPORT;
118	}
119
120	return (error);
121}
122
123#endif /* HAVE_BINDRESVPORT_SA */
124