1 /*
2 * Copyright (c) 1999 - 2001 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 22229 2007-12-08 21:40:59Z lha $");
37
38 static krb5_error_code
copy_hostname(krb5_context context,const char * orig_hostname,char ** new_hostname)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 krb5_set_error_string(context, "malloc: out of memory");
46 return ENOMEM;
47 }
48 strlwr (*new_hostname);
49 return 0;
50 }
51
52 /*
53 * Try to make `orig_hostname' into a more canonical one in the newly
54 * allocated space returned in `new_hostname'.
55 */
56
57 krb5_error_code KRB5_LIB_FUNCTION
krb5_expand_hostname(krb5_context context,const char * orig_hostname,char ** new_hostname)58 krb5_expand_hostname (krb5_context context,
59 const char *orig_hostname,
60 char **new_hostname)
61 {
62 struct addrinfo *ai, *a, hints;
63 int error;
64
65 if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
66 return copy_hostname (context, orig_hostname, new_hostname);
67
68 memset (&hints, 0, sizeof(hints));
69 hints.ai_flags = AI_CANONNAME;
70
71 error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
72 if (error)
73 return copy_hostname (context, orig_hostname, new_hostname);
74 for (a = ai; a != NULL; a = a->ai_next) {
75 if (a->ai_canonname != NULL) {
76 *new_hostname = strdup (a->ai_canonname);
77 freeaddrinfo (ai);
78 if (*new_hostname == NULL) {
79 krb5_set_error_string(context, "malloc: out of memory");
80 return ENOMEM;
81 } else {
82 return 0;
83 }
84 }
85 }
86 freeaddrinfo (ai);
87 return copy_hostname (context, orig_hostname, new_hostname);
88 }
89
90 /*
91 * handle the case of the hostname being unresolvable and thus identical
92 */
93
94 static krb5_error_code
vanilla_hostname(krb5_context context,const char * orig_hostname,char ** new_hostname,char *** realms)95 vanilla_hostname (krb5_context context,
96 const char *orig_hostname,
97 char **new_hostname,
98 char ***realms)
99 {
100 krb5_error_code ret;
101
102 ret = copy_hostname (context, orig_hostname, new_hostname);
103 if (ret)
104 return ret;
105 strlwr (*new_hostname);
106
107 ret = krb5_get_host_realm (context, *new_hostname, realms);
108 if (ret) {
109 free (*new_hostname);
110 return ret;
111 }
112 return 0;
113 }
114
115 /*
116 * expand `hostname' to a name we believe to be a hostname in newly
117 * allocated space in `host' and return realms in `realms'.
118 */
119
120 krb5_error_code KRB5_LIB_FUNCTION
krb5_expand_hostname_realms(krb5_context context,const char * orig_hostname,char ** new_hostname,char *** realms)121 krb5_expand_hostname_realms (krb5_context context,
122 const char *orig_hostname,
123 char **new_hostname,
124 char ***realms)
125 {
126 struct addrinfo *ai, *a, hints;
127 int error;
128 krb5_error_code ret = 0;
129
130 if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
131 return vanilla_hostname (context, orig_hostname, new_hostname,
132 realms);
133
134 memset (&hints, 0, sizeof(hints));
135 hints.ai_flags = AI_CANONNAME;
136
137 error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
138 if (error)
139 return vanilla_hostname (context, orig_hostname, new_hostname,
140 realms);
141
142 for (a = ai; a != NULL; a = a->ai_next) {
143 if (a->ai_canonname != NULL) {
144 ret = copy_hostname (context, a->ai_canonname, new_hostname);
145 if (ret) {
146 freeaddrinfo (ai);
147 return ret;
148 }
149 strlwr (*new_hostname);
150 ret = krb5_get_host_realm (context, *new_hostname, realms);
151 if (ret == 0) {
152 freeaddrinfo (ai);
153 return 0;
154 }
155 free (*new_hostname);
156 }
157 }
158 freeaddrinfo(ai);
159 return vanilla_hostname (context, orig_hostname, new_hostname, realms);
160 }
161