xref: /original-bsd/lib/librpc/rpc/bindresvport.c (revision c8876cb1)
1 static  char sccsid[] = "@(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC 1.8 88/02/08 SMI";
2 /*
3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4  * unrestricted use provided that this legend is included on all tape
5  * media and as a part of the software program in whole or part.  Users
6  * may copy or modify Sun RPC without charge, but are not authorized
7  * to license or distribute it to anyone else except as part of a product or
8  * program developed by the user.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  */
30 
31 /*
32  * Copyright (c) 1987 by Sun Microsystems, Inc.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/errno.h>
37 #include <sys/socket.h>
38 #include <netinet/in.h>
39 
40 /*
41  * Bind a socket to a privileged IP port
42  */
43 bindresvport(sd, sin)
44 	int sd;
45 	struct sockaddr_in *sin;
46 {
47 	int res;
48 	static short port;
49 	struct sockaddr_in myaddr;
50 	extern int errno;
51 	int i;
52 
53 #define STARTPORT 600
54 #define ENDPORT (IPPORT_RESERVED - 1)
55 #define NPORTS	(ENDPORT - STARTPORT + 1)
56 
57 	if (sin == (struct sockaddr_in *)0) {
58 		sin = &myaddr;
59 		bzero(sin, sizeof (*sin));
60 		sin->sin_family = AF_INET;
61 	} else if (sin->sin_family != AF_INET) {
62 		errno = EPFNOSUPPORT;
63 		return (-1);
64 	}
65 	if (port == 0) {
66 		port = (getpid() % NPORTS) + STARTPORT;
67 	}
68 	res = -1;
69 	errno = EADDRINUSE;
70 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
71 		sin->sin_port = htons(port++);
72 		if (port > ENDPORT) {
73 			port = STARTPORT;
74 		}
75 		res = bind(sd, sin, sizeof(struct sockaddr_in));
76 	}
77 	return (res);
78 }
79