xref: /netbsd-src/lib/libc/rpc/bindresvport.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: bindresvport.c,v 1.6 1996/03/29 23:00:50 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 #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";*/
35 static char *rcsid = "$NetBSD: bindresvport.c,v 1.6 1996/03/29 23:00:50 jtc 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  */
51 int
52 bindresvport(sd, sin)
53 	int sd;
54 	struct sockaddr_in *sin;
55 {
56 	int res;
57 	static short port;
58 	struct sockaddr_in myaddr;
59 	int i;
60 
61 #define STARTPORT 600
62 #define ENDPORT (IPPORT_RESERVED - 1)
63 #define NPORTS	(ENDPORT - STARTPORT + 1)
64 
65 	if (sin == (struct sockaddr_in *)0) {
66 		sin = &myaddr;
67 		memset(sin, 0, sizeof (*sin));
68 		sin->sin_len = sizeof(struct sockaddr_in);
69 		sin->sin_family = AF_INET;
70 	} else if (sin->sin_family != AF_INET) {
71 		errno = EPFNOSUPPORT;
72 		return (-1);
73 	}
74 	if (port == 0) {
75 		port = (getpid() % NPORTS) + STARTPORT;
76 	}
77 	res = -1;
78 	errno = EADDRINUSE;
79 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
80 		sin->sin_port = htons(port++);
81 		if (port > ENDPORT) {
82 			port = STARTPORT;
83 		}
84 		res = bind(sd,
85 		    (struct sockaddr *)sin, sizeof(struct sockaddr_in));
86 	}
87 	return (res);
88 }
89