xref: /titanic_44/usr/src/lib/libbc/libc/net/bindresvport.c (revision 8eea8e29cc4374d1ee24c25a07f45af132db3499)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 #pragma ident	"%Z%%M%	%I%	%E% SMI"
23 
24 /*
25  * Copyright 1987 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #include <sys/types.h>
30 #include <sys/errno.h>
31 #include <sys/socket.h>
32 #include <netinet/in.h>
33 
34 /*
35  * Bind a socket to a privileged IP port
36  */
37 bindresvport(sd, sin)
38 	int sd;
39 	struct sockaddr_in *sin;
40 {
41 	int res;
42 	static short port;
43 	struct sockaddr_in myaddr;
44 	extern int errno;
45 	int i;
46 
47 #define STARTPORT 600
48 #define ENDPORT (IPPORT_RESERVED - 1)
49 #define NPORTS	(ENDPORT - STARTPORT + 1)
50 
51 	if (sin == (struct sockaddr_in *)0) {
52 		sin = &myaddr;
53 		bzero(sin, sizeof (*sin));
54 		sin->sin_family = AF_INET;
55 	} else if (sin->sin_family != AF_INET) {
56 		errno = EPFNOSUPPORT;
57 		return (-1);
58 	}
59 	if (port == 0) {
60 		port = (getpid() % NPORTS) + STARTPORT;
61 	}
62 	res = -1;
63 	errno = EADDRINUSE;
64 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
65 		sin->sin_port = htons(port++);
66 		if (port > ENDPORT) {
67 			port = STARTPORT;
68 		}
69 		res = bind(sd, sin, sizeof(struct sockaddr_in));
70 	}
71 	return (res);
72 }
73