xref: /freebsd/crypto/heimdal/lib/krb5/expand_hostname.c (revision 5f1c68f7489c12bce03cdbe6af4faa34f7031683)
1 /*
2  * Copyright (c) 1999 - 2000 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
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  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "krb5_locl.h"
35 
36 RCSID("$Id: expand_hostname.c,v 1.5 2000/01/08 08:07:18 assar Exp $");
37 
38 static krb5_error_code
39 copy_hostname(krb5_context context,
40 	      const char *orig_hostname,
41 	      char **new_hostname)
42 {
43     *new_hostname = strdup (orig_hostname);
44     if (*new_hostname == NULL)
45 	return ENOMEM;
46     return 0;
47 }
48 
49 /*
50  * Try to make `orig_hostname' into a more canonical one in the newly
51  * allocated space returned in `new_hostname'.
52  */
53 
54 krb5_error_code
55 krb5_expand_hostname (krb5_context context,
56 		      const char *orig_hostname,
57 		      char **new_hostname)
58 {
59     struct addrinfo *ai, *a, hints;
60     int error;
61 
62     memset (&hints, 0, sizeof(hints));
63     hints.ai_flags = AI_CANONNAME;
64 
65     error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
66     if (error)
67 	return copy_hostname (context, orig_hostname, new_hostname);
68     for (a = ai; a != NULL; a = a->ai_next) {
69 	if (a->ai_canonname != NULL) {
70 	    *new_hostname = strdup (a->ai_canonname);
71 	    freeaddrinfo (ai);
72 	    if (*new_hostname == NULL)
73 		return ENOMEM;
74 	    else
75 		return 0;
76 	}
77     }
78     freeaddrinfo (ai);
79     return copy_hostname (context, orig_hostname, new_hostname);
80 }
81