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 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 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 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 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