xref: /freebsd/lib/libc/rpc/bindresvport.c (revision 8e6b01171e30297084bb0b4457c4183c2746aacc)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 /*static char *sccsid = "from: @(#)bindresvport.c 1.8 88/02/08 SMI";*/
32 /*static char *sccsid = "from: @(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";*/
33 static char *rcsid = "$Id: bindresvport.c,v 1.2 1995/05/30 05:41:13 rgrimes Exp $";
34 #endif
35 
36 /*
37  * Copyright (c) 1987 by Sun Microsystems, Inc.
38  */
39 
40 #include <sys/types.h>
41 #include <sys/errno.h>
42 #include <sys/socket.h>
43 #include <netinet/in.h>
44 #include <unistd.h>
45 #include <string.h>
46 
47 /*
48  * Bind a socket to a privileged IP port
49  */
50 bindresvport(sd, sin)
51 	int sd;
52 	struct sockaddr_in *sin;
53 {
54 	int res;
55 	static short port;
56 	struct sockaddr_in myaddr;
57 	extern int errno;
58 	int i;
59 
60 #define STARTPORT 600
61 #define ENDPORT (IPPORT_RESERVED - 1)
62 #define NPORTS	(ENDPORT - STARTPORT + 1)
63 
64 	if (sin == (struct sockaddr_in *)0) {
65 		sin = &myaddr;
66 		bzero(sin, sizeof (*sin));
67 		sin->sin_family = AF_INET;
68 	} else if (sin->sin_family != AF_INET) {
69 		errno = EPFNOSUPPORT;
70 		return (-1);
71 	}
72 	if (port == 0) {
73 		port = (getpid() % NPORTS) + STARTPORT;
74 	}
75 	res = -1;
76 	errno = EADDRINUSE;
77 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
78 		sin->sin_port = htons(port++);
79 		if (port > ENDPORT) {
80 			port = STARTPORT;
81 		}
82 		res = bind(sd,
83 		    (struct sockaddr *)sin, sizeof(struct sockaddr_in));
84 	}
85 	return (res);
86 }
87