xref: /csrg-svn/lib/librpc/rpc/bindresvport.c (revision 45074)
1*45074Smckusick static  char sccsid[] = "@(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC 1.8 88/02/08 SMI";
2*45074Smckusick /*
3*45074Smckusick  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4*45074Smckusick  * unrestricted use provided that this legend is included on all tape
5*45074Smckusick  * media and as a part of the software program in whole or part.  Users
6*45074Smckusick  * may copy or modify Sun RPC without charge, but are not authorized
7*45074Smckusick  * to license or distribute it to anyone else except as part of a product or
8*45074Smckusick  * program developed by the user.
9*45074Smckusick  *
10*45074Smckusick  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11*45074Smckusick  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12*45074Smckusick  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13*45074Smckusick  *
14*45074Smckusick  * Sun RPC is provided with no support and without any obligation on the
15*45074Smckusick  * part of Sun Microsystems, Inc. to assist in its use, correction,
16*45074Smckusick  * modification or enhancement.
17*45074Smckusick  *
18*45074Smckusick  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19*45074Smckusick  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20*45074Smckusick  * OR ANY PART THEREOF.
21*45074Smckusick  *
22*45074Smckusick  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23*45074Smckusick  * or profits or other special, indirect and consequential damages, even if
24*45074Smckusick  * Sun has been advised of the possibility of such damages.
25*45074Smckusick  *
26*45074Smckusick  * Sun Microsystems, Inc.
27*45074Smckusick  * 2550 Garcia Avenue
28*45074Smckusick  * Mountain View, California  94043
29*45074Smckusick  */
30*45074Smckusick 
31*45074Smckusick /*
32*45074Smckusick  * Copyright (c) 1987 by Sun Microsystems, Inc.
33*45074Smckusick  */
34*45074Smckusick 
35*45074Smckusick #include <sys/types.h>
36*45074Smckusick #include <sys/errno.h>
37*45074Smckusick #include <sys/socket.h>
38*45074Smckusick #include <netinet/in.h>
39*45074Smckusick 
40*45074Smckusick /*
41*45074Smckusick  * Bind a socket to a privileged IP port
42*45074Smckusick  */
43*45074Smckusick bindresvport(sd, sin)
44*45074Smckusick 	int sd;
45*45074Smckusick 	struct sockaddr_in *sin;
46*45074Smckusick {
47*45074Smckusick 	int res;
48*45074Smckusick 	static short port;
49*45074Smckusick 	struct sockaddr_in myaddr;
50*45074Smckusick 	extern int errno;
51*45074Smckusick 	int i;
52*45074Smckusick 
53*45074Smckusick #define STARTPORT 600
54*45074Smckusick #define ENDPORT (IPPORT_RESERVED - 1)
55*45074Smckusick #define NPORTS	(ENDPORT - STARTPORT + 1)
56*45074Smckusick 
57*45074Smckusick 	if (sin == (struct sockaddr_in *)0) {
58*45074Smckusick 		sin = &myaddr;
59*45074Smckusick 		bzero(sin, sizeof (*sin));
60*45074Smckusick 		sin->sin_family = AF_INET;
61*45074Smckusick 	} else if (sin->sin_family != AF_INET) {
62*45074Smckusick 		errno = EPFNOSUPPORT;
63*45074Smckusick 		return (-1);
64*45074Smckusick 	}
65*45074Smckusick 	if (port == 0) {
66*45074Smckusick 		port = (getpid() % NPORTS) + STARTPORT;
67*45074Smckusick 	}
68*45074Smckusick 	res = -1;
69*45074Smckusick 	errno = EADDRINUSE;
70*45074Smckusick 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
71*45074Smckusick 		sin->sin_port = htons(port++);
72*45074Smckusick 		if (port > ENDPORT) {
73*45074Smckusick 			port = STARTPORT;
74*45074Smckusick 		}
75*45074Smckusick 		res = bind(sd, sin, sizeof(struct sockaddr_in));
76*45074Smckusick 	}
77*45074Smckusick 	return (res);
78*45074Smckusick }
79