xref: /freebsd/crypto/openssh/openbsd-compat/rresvport.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
1 /* $OpenBSD: rresvport.c,v 1.9 2005/11/10 10:00:17 espie Exp $ */
2 /*
3  * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
4  * Copyright (c) 1983, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /* OPENBSD ORIGINAL: lib/libc/net/rresvport.c */
33 
34 #include "includes.h"
35 
36 #ifndef HAVE_RRESVPORT_AF
37 
38 #if 0
39 int
40 rresvport(int *alport)
41 {
42 	return rresvport_af(alport, AF_INET);
43 }
44 #endif
45 
46 int
47 rresvport_af(int *alport, sa_family_t af)
48 {
49 	struct sockaddr_storage ss;
50 	struct sockaddr *sa;
51 	u_int16_t *portp;
52 	int s;
53 	socklen_t salen;
54 
55 	memset(&ss, '\0', sizeof ss);
56 	sa = (struct sockaddr *)&ss;
57 
58 	switch (af) {
59 	case AF_INET:
60 		salen = sizeof(struct sockaddr_in);
61 		portp = &((struct sockaddr_in *)sa)->sin_port;
62 		break;
63 	case AF_INET6:
64 		salen = sizeof(struct sockaddr_in6);
65 		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
66 		break;
67 	default:
68 		errno = EPFNOSUPPORT;
69 		return (-1);
70 	}
71 	sa->sa_family = af;
72 
73 	s = socket(af, SOCK_STREAM, 0);
74 	if (s < 0)
75 		return (-1);
76 
77 	*portp = htons(*alport);
78 	if (*alport < IPPORT_RESERVED - 1) {
79 		if (bind(s, sa, salen) >= 0)
80 			return (s);
81 		if (errno != EADDRINUSE) {
82 			(void)close(s);
83 			return (-1);
84 		}
85 	}
86 
87 	*portp = 0;
88 	sa->sa_family = af;
89 	if (bindresvport_sa(s, sa) == -1) {
90 		(void)close(s);
91 		return (-1);
92 	}
93 	*alport = ntohs(*portp);
94 	return (s);
95 }
96 
97 #endif /* HAVE_RRESVPORT_AF */
98