bindresvport.c revision 1.7 
1/*	$NetBSD: bindresvport.c,v 1.7 1997/07/13 20:13:04 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 1.7 1997/07/13 20:13:04 christos Exp $");
39#endif
40#endif
41
42/*
43 * Copyright (c) 1987 by Sun Microsystems, Inc.
44 */
45
46#include <string.h>
47#include <unistd.h>
48#include <sys/types.h>
49#include <sys/errno.h>
50#include <sys/socket.h>
51#include <netinet/in.h>
52#include <rpc/rpc.h>
53
54/*
55 * Bind a socket to a privileged IP port
56 */
57int
58bindresvport(sd, sin)
59	int sd;
60	struct sockaddr_in *sin;
61{
62	int res;
63	static short port;
64	struct sockaddr_in myaddr;
65	int i;
66
67#define STARTPORT 600
68#define ENDPORT (IPPORT_RESERVED - 1)
69#define NPORTS	(ENDPORT - STARTPORT + 1)
70
71	if (sin == (struct sockaddr_in *)0) {
72		sin = &myaddr;
73		memset(sin, 0, sizeof (*sin));
74		sin->sin_len = sizeof(struct sockaddr_in);
75		sin->sin_family = AF_INET;
76	} else if (sin->sin_family != AF_INET) {
77		errno = EPFNOSUPPORT;
78		return (-1);
79	}
80	if (port == 0) {
81		port = (getpid() % NPORTS) + STARTPORT;
82	}
83	res = -1;
84	errno = EADDRINUSE;
85	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
86		sin->sin_port = htons(port++);
87		if (port > ENDPORT) {
88			port = STARTPORT;
89		}
90		res = bind(sd,
91		    (struct sockaddr *)sin, sizeof(struct sockaddr_in));
92	}
93	return (res);
94}
95