xref: /freebsd/crypto/heimdal/lib/krb5/get_addrs.c (revision 63a938566d524836885917d95bd491aa4400b181)
1 /*
2  * Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
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 #ifdef __osf__
37 /* hate */
38 struct rtentry;
39 struct mbuf;
40 #endif
41 #ifdef HAVE_NET_IF_H
42 #include <net/if.h>
43 #endif
44 #include <ifaddrs.h>
45 
46 static krb5_error_code
47 gethostname_fallback (krb5_context context, krb5_addresses *res)
48 {
49     krb5_error_code ret;
50     char hostname[MAXHOSTNAMELEN];
51     struct hostent *hostent;
52 
53     if (gethostname (hostname, sizeof(hostname))) {
54 	ret = errno;
55 	krb5_set_error_message(context, ret, "gethostname: %s", strerror(ret));
56 	return ret;
57     }
58     hostent = roken_gethostbyname (hostname);
59     if (hostent == NULL) {
60 	ret = errno;
61 	krb5_set_error_message (context, ret, "gethostbyname %s: %s",
62 				hostname, strerror(ret));
63 	return ret;
64     }
65     res->len = 1;
66     res->val = malloc (sizeof(*res->val));
67     if (res->val == NULL) {
68 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
69 	return ENOMEM;
70     }
71     res->val[0].addr_type = hostent->h_addrtype;
72     res->val[0].address.data = NULL;
73     res->val[0].address.length = 0;
74     ret = krb5_data_copy (&res->val[0].address,
75 			  hostent->h_addr,
76 			  hostent->h_length);
77     if (ret) {
78 	free (res->val);
79 	return ret;
80     }
81     return 0;
82 }
83 
84 enum {
85     LOOP            = 1,	/* do include loopback addrs */
86     LOOP_IF_NONE    = 2,	/* include loopback addrs if no others */
87     EXTRA_ADDRESSES = 4,	/* include extra addresses */
88     SCAN_INTERFACES = 8		/* scan interfaces for addresses */
89 };
90 
91 /*
92  * Try to figure out the addresses of all configured interfaces with a
93  * lot of magic ioctls.
94  */
95 
96 static krb5_error_code
97 find_all_addresses (krb5_context context, krb5_addresses *res, int flags)
98 {
99     struct sockaddr sa_zero;
100     struct ifaddrs *ifa0, *ifa;
101     krb5_error_code ret = ENXIO;
102     unsigned int num, idx;
103     krb5_addresses ignore_addresses;
104 
105     if (getifaddrs(&ifa0) == -1) {
106 	ret = errno;
107 	krb5_set_error_message(context, ret, "getifaddrs: %s", strerror(ret));
108 	return (ret);
109     }
110 
111     memset(&sa_zero, 0, sizeof(sa_zero));
112 
113     /* First, count all the ifaddrs. */
114     for (ifa = ifa0, num = 0; ifa != NULL; ifa = ifa->ifa_next, num++)
115 	/* nothing */;
116 
117     if (num == 0) {
118 	freeifaddrs(ifa0);
119 	krb5_set_error_message(context, ENXIO, N_("no addresses found", ""));
120 	return (ENXIO);
121     }
122 
123     if (flags & EXTRA_ADDRESSES) {
124 	/* we'll remove the addresses we don't care about */
125 	ret = krb5_get_ignore_addresses(context, &ignore_addresses);
126 	if(ret)
127 	    return ret;
128     }
129 
130     /* Allocate storage for them. */
131     res->val = calloc(num, sizeof(*res->val));
132     if (res->val == NULL) {
133 	krb5_free_addresses(context, &ignore_addresses);
134 	freeifaddrs(ifa0);
135 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
136 	return ENOMEM;
137     }
138 
139     /* Now traverse the list. */
140     for (ifa = ifa0, idx = 0; ifa != NULL; ifa = ifa->ifa_next) {
141 	if ((ifa->ifa_flags & IFF_UP) == 0)
142 	    continue;
143 	if (ifa->ifa_addr == NULL)
144 	    continue;
145 	if (memcmp(ifa->ifa_addr, &sa_zero, sizeof(sa_zero)) == 0)
146 	    continue;
147 	if (krb5_sockaddr_uninteresting(ifa->ifa_addr))
148 	    continue;
149 	if (krb5_sockaddr_is_loopback(ifa->ifa_addr) && (flags & LOOP) == 0)
150 	    /* We'll deal with the LOOP_IF_NONE case later. */
151 	    continue;
152 
153 	ret = krb5_sockaddr2address(context, ifa->ifa_addr, &res->val[idx]);
154 	if (ret) {
155 	    /*
156 	     * The most likely error here is going to be "Program
157 	     * lacks support for address type".  This is no big
158 	     * deal -- just continue, and we'll listen on the
159 	     * addresses who's type we *do* support.
160 	     */
161 	    continue;
162 	}
163 	/* possibly skip this address? */
164 	if((flags & EXTRA_ADDRESSES) &&
165 	   krb5_address_search(context, &res->val[idx], &ignore_addresses)) {
166 	    krb5_free_address(context, &res->val[idx]);
167 	    flags &= ~LOOP_IF_NONE; /* we actually found an address,
168                                        so don't add any loop-back
169                                        addresses */
170 	    continue;
171 	}
172 
173 	idx++;
174     }
175 
176     /*
177      * If no addresses were found, and LOOP_IF_NONE is set, then find
178      * the loopback addresses and add them to our list.
179      */
180     if ((flags & LOOP_IF_NONE) != 0 && idx == 0) {
181 	for (ifa = ifa0; ifa != NULL; ifa = ifa->ifa_next) {
182 	    if ((ifa->ifa_flags & IFF_UP) == 0)
183 		continue;
184 	    if (ifa->ifa_addr == NULL)
185 		continue;
186 	    if (memcmp(ifa->ifa_addr, &sa_zero, sizeof(sa_zero)) == 0)
187 		continue;
188 	    if (krb5_sockaddr_uninteresting(ifa->ifa_addr))
189 		continue;
190 	    if (!krb5_sockaddr_is_loopback(ifa->ifa_addr))
191 		continue;
192 	    if ((ifa->ifa_flags & IFF_LOOPBACK) == 0)
193 		/* Presumably loopback addrs are only used on loopback ifs! */
194 		continue;
195 	    ret = krb5_sockaddr2address(context,
196 					ifa->ifa_addr, &res->val[idx]);
197 	    if (ret)
198 		continue; /* We don't consider this failure fatal */
199 	    if((flags & EXTRA_ADDRESSES) &&
200 	       krb5_address_search(context, &res->val[idx],
201 				   &ignore_addresses)) {
202 		krb5_free_address(context, &res->val[idx]);
203 		continue;
204 	    }
205 	    idx++;
206 	}
207     }
208 
209     if (flags & EXTRA_ADDRESSES)
210 	krb5_free_addresses(context, &ignore_addresses);
211     freeifaddrs(ifa0);
212     if (ret) {
213 	free(res->val);
214 	res->val = NULL;
215     } else
216 	res->len = idx;        /* Now a count. */
217     return (ret);
218 }
219 
220 static krb5_error_code
221 get_addrs_int (krb5_context context, krb5_addresses *res, int flags)
222 {
223     krb5_error_code ret = -1;
224 
225     res->len = 0;
226     res->val = NULL;
227 
228     if (flags & SCAN_INTERFACES) {
229 	ret = find_all_addresses (context, res, flags);
230 	if(ret || res->len == 0)
231 	    ret = gethostname_fallback (context, res);
232     } else {
233 	ret = 0;
234     }
235 
236     if(ret == 0 && (flags & EXTRA_ADDRESSES)) {
237 	krb5_addresses a;
238 	/* append user specified addresses */
239 	ret = krb5_get_extra_addresses(context, &a);
240 	if(ret) {
241 	    krb5_free_addresses(context, res);
242 	    return ret;
243 	}
244 	ret = krb5_append_addresses(context, res, &a);
245 	if(ret) {
246 	    krb5_free_addresses(context, res);
247 	    return ret;
248 	}
249 	krb5_free_addresses(context, &a);
250     }
251     if(res->len == 0) {
252 	free(res->val);
253 	res->val = NULL;
254     }
255     return ret;
256 }
257 
258 /*
259  * Try to get all addresses, but return the one corresponding to
260  * `hostname' if we fail.
261  *
262  * Only include loopback address if there are no other.
263  */
264 
265 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
266 krb5_get_all_client_addrs (krb5_context context, krb5_addresses *res)
267 {
268     int flags = LOOP_IF_NONE | EXTRA_ADDRESSES;
269 
270     if (context->scan_interfaces)
271 	flags |= SCAN_INTERFACES;
272 
273     return get_addrs_int (context, res, flags);
274 }
275 
276 /*
277  * Try to get all local addresses that a server should listen to.
278  * If that fails, we return the address corresponding to `hostname'.
279  */
280 
281 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
282 krb5_get_all_server_addrs (krb5_context context, krb5_addresses *res)
283 {
284     return get_addrs_int (context, res, LOOP | SCAN_INTERFACES);
285 }
286