xref: /dragonfly/lib/libc/rpc/bindresvport.c (revision 650094e1)
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  * @(#)bindresvport.c 1.8 88/02/08 SMI
30  * @(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC
31  * $NetBSD: bindresvport.c,v 1.19 2000/07/06 03:03:59 christos Exp $
32  * $FreeBSD: src/lib/libc/rpc/bindresvport.c,v 1.16 2004/10/16 06:11:34 obrien Exp $
33  */
34 
35 /*
36  * Copyright (c) 1987 by Sun Microsystems, Inc.
37  *
38  * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
39  */
40 
41 #include "namespace.h"
42 #include <sys/types.h>
43 #include <sys/socket.h>
44 
45 #include <netinet/in.h>
46 
47 #include <errno.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include <rpc/rpc.h>
52 #include "un-namespace.h"
53 
54 /*
55  * Bind a socket to a privileged IP port
56  */
57 int
58 bindresvport(int sd, struct sockaddr_in *sin)
59 {
60 	return bindresvport_sa(sd, (struct sockaddr *)sin);
61 }
62 
63 /*
64  * Bind a socket to a privileged IP port
65  */
66 int
67 bindresvport_sa(int sd, struct sockaddr *sa)
68 {
69 	int old, error, af;
70 	struct sockaddr_storage myaddr;
71 	struct sockaddr_in *sin;
72 #ifdef INET6
73 	struct sockaddr_in6 *sin6;
74 #endif
75 	int proto, portrange, portlow;
76 	u_int16_t *portp;
77 	socklen_t salen;
78 
79 	if (sa == NULL) {
80 		salen = sizeof(myaddr);
81 		sa = (struct sockaddr *)&myaddr;
82 
83 		if (_getsockname(sd, sa, &salen) == -1)
84 			return -1;	/* errno is correctly set */
85 
86 		af = sa->sa_family;
87 		memset(sa, 0, salen);
88 	} else
89 		af = sa->sa_family;
90 
91 	switch (af) {
92 	case AF_INET:
93 		proto = IPPROTO_IP;
94 		portrange = IP_PORTRANGE;
95 		portlow = IP_PORTRANGE_LOW;
96 		sin = (struct sockaddr_in *)sa;
97 		salen = sizeof(struct sockaddr_in);
98 		portp = &sin->sin_port;
99 		break;
100 #ifdef INET6
101 	case AF_INET6:
102 		proto = IPPROTO_IPV6;
103 		portrange = IPV6_PORTRANGE;
104 		portlow = IPV6_PORTRANGE_LOW;
105 		sin6 = (struct sockaddr_in6 *)sa;
106 		salen = sizeof(struct sockaddr_in6);
107 		portp = &sin6->sin6_port;
108 		break;
109 #endif
110 	default:
111 		errno = EPFNOSUPPORT;
112 		return (-1);
113 	}
114 	sa->sa_family = af;
115 	sa->sa_len = salen;
116 
117 	if (*portp == 0) {
118 		socklen_t oldlen = sizeof(old);
119 
120 		error = _getsockopt(sd, proto, portrange, &old, &oldlen);
121 		if (error < 0)
122 			return (error);
123 
124 		error = _setsockopt(sd, proto, portrange, &portlow,
125 		    sizeof(portlow));
126 		if (error < 0)
127 			return (error);
128 	}
129 
130 	error = _bind(sd, sa, salen);
131 
132 	if (*portp == 0) {
133 		int saved_errno = errno;
134 
135 		if (error < 0) {
136 			if (_setsockopt(sd, proto, portrange, &old,
137 			    sizeof(old)) < 0)
138 				errno = saved_errno;
139 			return (error);
140 		}
141 
142 		if (sa != (struct sockaddr *)&myaddr) {
143 			/* Hmm, what did the kernel assign? */
144 			if (_getsockname(sd, sa, &salen) < 0)
145 				errno = saved_errno;
146 			return (error);
147 		}
148 	}
149 	return (error);
150 }
151