xref: /freebsd/crypto/openssh/openbsd-compat/rresvport.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1 /* OPENBSD ORIGINAL: lib/libc/net/rresvport.c */
2 
3 /*
4  * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
5  * Copyright (c) 1983, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "includes.h"
34 
35 #ifndef HAVE_RRESVPORT_AF
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char *rcsid = "$OpenBSD: rresvport.c,v 1.6 2003/06/03 02:11:35 deraadt Exp $";
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "includes.h"
42 
43 #if 0
44 int
45 rresvport(alport)
46 	int *alport;
47 {
48 	return rresvport_af(alport, AF_INET);
49 }
50 #endif
51 
52 int
53 rresvport_af(int *alport, sa_family_t af)
54 {
55 	struct sockaddr_storage ss;
56 	struct sockaddr *sa;
57 	u_int16_t *portp;
58 	int s;
59 	socklen_t salen;
60 
61 	memset(&ss, '\0', sizeof ss);
62 	sa = (struct sockaddr *)&ss;
63 
64 	switch (af) {
65 	case AF_INET:
66 		salen = sizeof(struct sockaddr_in);
67 		portp = &((struct sockaddr_in *)sa)->sin_port;
68 		break;
69 	case AF_INET6:
70 		salen = sizeof(struct sockaddr_in6);
71 		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
72 		break;
73 	default:
74 		errno = EPFNOSUPPORT;
75 		return (-1);
76 	}
77 	sa->sa_family = af;
78 
79 	s = socket(af, SOCK_STREAM, 0);
80 	if (s < 0)
81 		return (-1);
82 
83 	*portp = htons(*alport);
84 	if (*alport < IPPORT_RESERVED - 1) {
85 		if (bind(s, sa, salen) >= 0)
86 			return (s);
87 		if (errno != EADDRINUSE) {
88 			(void)close(s);
89 			return (-1);
90 		}
91 	}
92 
93 	*portp = 0;
94 	sa->sa_family = af;
95 	if (bindresvport_sa(s, sa) == -1) {
96 		(void)close(s);
97 		return (-1);
98 	}
99 	*alport = ntohs(*portp);
100 	return (s);
101 }
102 
103 #endif /* HAVE_RRESVPORT_AF */
104