xref: /freebsd/crypto/openssh/openbsd-compat/rresvport.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 #include <sys/types.h>
39 #include <sys/socket.h>
40 
41 #include <netinet/in.h>
42 #include <arpa/inet.h>
43 
44 #include <errno.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #if 0
50 int
51 rresvport(int *alport)
52 {
53 	return rresvport_af(alport, AF_INET);
54 }
55 #endif
56 
57 int
58 rresvport_af(int *alport, sa_family_t af)
59 {
60 	struct sockaddr_storage ss;
61 	struct sockaddr *sa;
62 	u_int16_t *portp;
63 	int s;
64 	socklen_t salen;
65 
66 	memset(&ss, '\0', sizeof ss);
67 	sa = (struct sockaddr *)&ss;
68 
69 	switch (af) {
70 	case AF_INET:
71 		salen = sizeof(struct sockaddr_in);
72 		portp = &((struct sockaddr_in *)sa)->sin_port;
73 		break;
74 	case AF_INET6:
75 		salen = sizeof(struct sockaddr_in6);
76 		portp = &((struct sockaddr_in6 *)sa)->sin6_port;
77 		break;
78 	default:
79 		errno = EPFNOSUPPORT;
80 		return (-1);
81 	}
82 	sa->sa_family = af;
83 
84 	s = socket(af, SOCK_STREAM, 0);
85 	if (s < 0)
86 		return (-1);
87 
88 	*portp = htons(*alport);
89 	if (*alport < IPPORT_RESERVED - 1) {
90 		if (bind(s, sa, salen) >= 0)
91 			return (s);
92 		if (errno != EADDRINUSE) {
93 			(void)close(s);
94 			return (-1);
95 		}
96 	}
97 
98 	*portp = 0;
99 	sa->sa_family = af;
100 	if (bindresvport_sa(s, sa) == -1) {
101 		(void)close(s);
102 		return (-1);
103 	}
104 	*alport = ntohs(*portp);
105 	return (s);
106 }
107 
108 #endif /* HAVE_RRESVPORT_AF */
109