xref: /freebsd/lib/libc/rpc/bindresvport.c (revision 380a989b3223d455375b4fae70fd0b9bdd43bafb)
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 /*from: OpenBSD: bindresvport.c,v 1.7 1996/07/30 16:25:47 downsj Exp */
34 static char *rcsid = "$Id: bindresvport.c,v 1.6 1996/12/30 14:12:36 peter Exp $";
35 #endif
36 
37 /*
38  * Copyright (c) 1987 by Sun Microsystems, Inc.
39  *
40  * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
41  */
42 
43 #include <sys/types.h>
44 #include <sys/errno.h>
45 #include <sys/socket.h>
46 #include <netinet/in.h>
47 #include <unistd.h>
48 #include <string.h>
49 
50 /*
51  * Bind a socket to a privileged IP port
52  */
53 int
54 bindresvport(sd, sin)
55 	int sd;
56 	struct sockaddr_in *sin;
57 {
58 	int on, old, error;
59 	struct sockaddr_in myaddr;
60 	int sinlen = sizeof(struct sockaddr_in);
61 
62 	if (sin == (struct sockaddr_in *)0) {
63 		sin = &myaddr;
64 		memset(sin, 0, sinlen);
65 		sin->sin_len = sinlen;
66 		sin->sin_family = AF_INET;
67 	} else if (sin->sin_family != AF_INET) {
68 		errno = EPFNOSUPPORT;
69 		return (-1);
70 	}
71 
72 	if (sin->sin_port == 0) {
73 		int oldlen = sizeof(old);
74 		error = getsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
75 				   &old, &oldlen);
76 		if (error < 0)
77 			return(error);
78 
79 		on = IP_PORTRANGE_LOW;
80 		error = setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
81 		           	   &on, sizeof(on));
82 		if (error < 0)
83 			return(error);
84 	}
85 
86 	error = bind(sd, (struct sockaddr *)sin, sinlen);
87 
88 	if (sin->sin_port == 0) {
89 		int saved_errno = errno;
90 
91 		if (error) {
92 			if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
93 			    &old, sizeof(old)) < 0)
94 				errno = saved_errno;
95 			return (error);
96 		}
97 
98 		if (sin != &myaddr) {
99 			/* Hmm, what did the kernel assign... */
100 			if (getsockname(sd, (struct sockaddr *)sin,
101 			    &sinlen) < 0)
102 				errno = saved_errno;
103 			return (error);
104 		}
105 	}
106 	return (error);
107 }
108