xref: /netbsd-src/lib/libc/rpc/bindresvport.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: bindresvport.c,v 1.8 1997/07/21 14:08:21 jtc 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
35 static char *sccsid = "@(#)bindresvport.c 1.8 88/02/08 SMI";
36 static char *sccsid = "@(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";
37 #else
38 __RCSID("$NetBSD: bindresvport.c,v 1.8 1997/07/21 14:08:21 jtc Exp $");
39 #endif
40 #endif
41 
42 /*
43  * Copyright (c) 1987 by Sun Microsystems, Inc.
44  */
45 
46 #include "namespace.h"
47 #include <string.h>
48 #include <unistd.h>
49 #include <sys/types.h>
50 #include <sys/errno.h>
51 #include <sys/socket.h>
52 #include <netinet/in.h>
53 #include <rpc/rpc.h>
54 
55 #ifdef __weak_alias
56 __weak_alias(bindresvport,_bindresvport);
57 #endif
58 
59 /*
60  * Bind a socket to a privileged IP port
61  */
62 int
63 bindresvport(sd, sin)
64 	int sd;
65 	struct sockaddr_in *sin;
66 {
67 	int res;
68 	static short port;
69 	struct sockaddr_in myaddr;
70 	int i;
71 
72 #define STARTPORT 600
73 #define ENDPORT (IPPORT_RESERVED - 1)
74 #define NPORTS	(ENDPORT - STARTPORT + 1)
75 
76 	if (sin == (struct sockaddr_in *)0) {
77 		sin = &myaddr;
78 		memset(sin, 0, sizeof (*sin));
79 		sin->sin_len = sizeof(struct sockaddr_in);
80 		sin->sin_family = AF_INET;
81 	} else if (sin->sin_family != AF_INET) {
82 		errno = EPFNOSUPPORT;
83 		return (-1);
84 	}
85 	if (port == 0) {
86 		port = (getpid() % NPORTS) + STARTPORT;
87 	}
88 	res = -1;
89 	errno = EADDRINUSE;
90 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
91 		sin->sin_port = htons(port++);
92 		if (port > ENDPORT) {
93 			port = STARTPORT;
94 		}
95 		res = bind(sd,
96 		    (struct sockaddr *)sin, sizeof(struct sockaddr_in));
97 	}
98 	return (res);
99 }
100