bindresvport.c revision 1.5 
1/*	$NetBSD: bindresvport.c,v 1.5 1995/06/03 22:37:19 mycroft 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#if defined(LIBC_SCCS) && !defined(lint)
33/*static char *sccsid = "from: @(#)bindresvport.c 1.8 88/02/08 SMI";*/
34/*static char *sccsid = "from: @(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";*/
35static char *rcsid = "$NetBSD: bindresvport.c,v 1.5 1995/06/03 22:37:19 mycroft Exp $";
36#endif
37
38/*
39 * Copyright (c) 1987 by Sun Microsystems, Inc.
40 */
41
42#include <string.h>
43#include <sys/types.h>
44#include <sys/errno.h>
45#include <sys/socket.h>
46#include <netinet/in.h>
47
48/*
49 * Bind a socket to a privileged IP port
50 */
51bindresvport(sd, sin)
52	int sd;
53	struct sockaddr_in *sin;
54{
55	int res;
56	static short port;
57	struct sockaddr_in myaddr;
58	int i;
59
60#define STARTPORT 600
61#define ENDPORT (IPPORT_RESERVED - 1)
62#define NPORTS	(ENDPORT - STARTPORT + 1)
63
64	if (sin == (struct sockaddr_in *)0) {
65		sin = &myaddr;
66		memset(sin, 0, sizeof (*sin));
67		sin->sin_len = sizeof(struct sockaddr_in);
68		sin->sin_family = AF_INET;
69	} else if (sin->sin_family != AF_INET) {
70		errno = EPFNOSUPPORT;
71		return (-1);
72	}
73	if (port == 0) {
74		port = (getpid() % NPORTS) + STARTPORT;
75	}
76	res = -1;
77	errno = EADDRINUSE;
78	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
79		sin->sin_port = htons(port++);
80		if (port > ENDPORT) {
81			port = STARTPORT;
82		}
83		res = bind(sd,
84		    (struct sockaddr *)sin, sizeof(struct sockaddr_in));
85	}
86	return (res);
87}
88