1 /* $NetBSD: expand_hostname.c,v 1.1.1.1 2011/04/13 18:15:33 elric Exp $ */
2
3 /*
4 * Copyright (c) 1999 - 2001 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * 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 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include "krb5_locl.h"
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_message(context, ENOMEM,
46 N_("malloc: out of memory", ""));
47 return ENOMEM;
48 }
49 strlwr (*new_hostname);
50 return 0;
51 }
52
53 /**
54 * krb5_expand_hostname() tries to make orig_hostname into a more
55 * canonical one in the newly allocated space returned in
56 * new_hostname.
57
58 * @param context a Keberos context
59 * @param orig_hostname hostname to canonicalise.
60 * @param new_hostname output hostname, caller must free hostname with
61 * krb5_xfree().
62 *
63 * @return Return an error code or 0, see krb5_get_error_message().
64 *
65 * @ingroup krb5_support
66 */
67
68 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_expand_hostname(krb5_context context,const char * orig_hostname,char ** new_hostname)69 krb5_expand_hostname (krb5_context context,
70 const char *orig_hostname,
71 char **new_hostname)
72 {
73 struct addrinfo *ai, *a, hints;
74 int error;
75
76 if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
77 return copy_hostname (context, orig_hostname, new_hostname);
78
79 memset (&hints, 0, sizeof(hints));
80 hints.ai_flags = AI_CANONNAME;
81
82 error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
83 if (error)
84 return copy_hostname (context, orig_hostname, new_hostname);
85 for (a = ai; a != NULL; a = a->ai_next) {
86 if (a->ai_canonname != NULL) {
87 *new_hostname = strdup (a->ai_canonname);
88 freeaddrinfo (ai);
89 if (*new_hostname == NULL) {
90 krb5_set_error_message(context, ENOMEM,
91 N_("malloc: out of memory", ""));
92 return ENOMEM;
93 } else {
94 return 0;
95 }
96 }
97 }
98 freeaddrinfo (ai);
99 return copy_hostname (context, orig_hostname, new_hostname);
100 }
101
102 /*
103 * handle the case of the hostname being unresolvable and thus identical
104 */
105
106 static krb5_error_code
vanilla_hostname(krb5_context context,const char * orig_hostname,char ** new_hostname,char *** realms)107 vanilla_hostname (krb5_context context,
108 const char *orig_hostname,
109 char **new_hostname,
110 char ***realms)
111 {
112 krb5_error_code ret;
113
114 ret = copy_hostname (context, orig_hostname, new_hostname);
115 if (ret)
116 return ret;
117 strlwr (*new_hostname);
118
119 ret = krb5_get_host_realm (context, *new_hostname, realms);
120 if (ret) {
121 free (*new_hostname);
122 return ret;
123 }
124 return 0;
125 }
126
127 /**
128 * krb5_expand_hostname_realms() expands orig_hostname to a name we
129 * believe to be a hostname in newly allocated space in new_hostname
130 * and return the realms new_hostname is believed to belong to in
131 * realms.
132 *
133 * @param context a Keberos context
134 * @param orig_hostname hostname to canonicalise.
135 * @param new_hostname output hostname, caller must free hostname with
136 * krb5_xfree().
137 * @param realms output possible realms, is an array that is terminated
138 * with NULL. Caller must free with krb5_free_host_realm().
139 *
140 * @return Return an error code or 0, see krb5_get_error_message().
141 *
142 * @ingroup krb5_support
143 */
144
145 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_expand_hostname_realms(krb5_context context,const char * orig_hostname,char ** new_hostname,char *** realms)146 krb5_expand_hostname_realms (krb5_context context,
147 const char *orig_hostname,
148 char **new_hostname,
149 char ***realms)
150 {
151 struct addrinfo *ai, *a, hints;
152 int error;
153 krb5_error_code ret = 0;
154
155 if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
156 return vanilla_hostname (context, orig_hostname, new_hostname,
157 realms);
158
159 memset (&hints, 0, sizeof(hints));
160 hints.ai_flags = AI_CANONNAME;
161
162 error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
163 if (error)
164 return vanilla_hostname (context, orig_hostname, new_hostname,
165 realms);
166
167 for (a = ai; a != NULL; a = a->ai_next) {
168 if (a->ai_canonname != NULL) {
169 ret = copy_hostname (context, a->ai_canonname, new_hostname);
170 if (ret) {
171 freeaddrinfo (ai);
172 return ret;
173 }
174 strlwr (*new_hostname);
175 ret = krb5_get_host_realm (context, *new_hostname, realms);
176 if (ret == 0) {
177 freeaddrinfo (ai);
178 return 0;
179 }
180 free (*new_hostname);
181 }
182 }
183 freeaddrinfo(ai);
184 return vanilla_hostname (context, orig_hostname, new_hostname, realms);
185 }
186