xref: /freebsd/crypto/heimdal/lib/krb5/get_addrs.c (revision 362982da86a3a7ce3c55e669032f8c22a2a6b4e0)
1 /*
2  * Copyright (c) 1997 - 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: get_addrs.c,v 1.41 2001/05/14 06:14:46 assar Exp $");
37 
38 #ifdef __osf__
39 /* hate */
40 struct rtentry;
41 struct mbuf;
42 #endif
43 #ifdef HAVE_NET_IF_H
44 #include <net/if.h>
45 #endif
46 #include <ifaddrs.h>
47 
48 static krb5_error_code
49 gethostname_fallback (krb5_context context, krb5_addresses *res)
50 {
51     krb5_error_code ret;
52     char hostname[MAXHOSTNAMELEN];
53     struct hostent *hostent;
54 
55     if (gethostname (hostname, sizeof(hostname))) {
56 	ret = errno;
57 	krb5_set_error_string (context, "gethostname: %s", strerror(ret));
58 	return ret;
59     }
60     hostent = roken_gethostbyname (hostname);
61     if (hostent == NULL) {
62 	ret = errno;
63 	krb5_set_error_string (context, "gethostbyname %s: %s",
64 			       hostname, strerror(ret));
65 	return ret;
66     }
67     res->len = 1;
68     res->val = malloc (sizeof(*res->val));
69     if (res->val == NULL) {
70 	krb5_set_error_string(context, "malloc: out of memory");
71 	return ENOMEM;
72     }
73     res->val[0].addr_type = hostent->h_addrtype;
74     res->val[0].address.data = NULL;
75     res->val[0].address.length = 0;
76     ret = krb5_data_copy (&res->val[0].address,
77 			  hostent->h_addr,
78 			  hostent->h_length);
79     if (ret) {
80 	free (res->val);
81 	return ret;
82     }
83     return 0;
84 }
85 
86 enum {
87     LOOP            = 1,	/* do include loopback interfaces */
88     LOOP_IF_NONE    = 2,	/* include loopback if no other if's */
89     EXTRA_ADDRESSES = 4,	/* include extra addresses */
90     SCAN_INTERFACES = 8		/* scan interfaces for addresses */
91 };
92 
93 /*
94  * Try to figure out the addresses of all configured interfaces with a
95  * lot of magic ioctls.
96  */
97 
98 static krb5_error_code
99 find_all_addresses (krb5_context context, krb5_addresses *res, int flags)
100 {
101     struct sockaddr sa_zero;
102     struct ifaddrs *ifa0, *ifa;
103     krb5_error_code ret = ENXIO;
104     int num, idx;
105 
106     res->val = NULL;
107 
108     if (getifaddrs(&ifa0) == -1) {
109 	ret = errno;
110 	krb5_set_error_string(context, "getifaddrs: %s", strerror(ret));
111 	return (ret);
112     }
113 
114     memset(&sa_zero, 0, sizeof(sa_zero));
115 
116     /* First, count all the ifaddrs. */
117     for (ifa = ifa0, num = 0; ifa != NULL; ifa = ifa->ifa_next, num++)
118 	/* nothing */;
119 
120     if (num == 0) {
121 	freeifaddrs(ifa0);
122 	krb5_set_error_string(context, "no addresses found");
123 	return (ENXIO);
124     }
125 
126     /* Allocate storage for them. */
127     res->val = calloc(num, sizeof(*res->val));
128     if (res->val == NULL) {
129 	freeifaddrs(ifa0);
130 	krb5_set_error_string (context, "malloc: out of memory");
131 	return (ENOMEM);
132     }
133 
134     /* Now traverse the list. */
135     for (ifa = ifa0, idx = 0; ifa != NULL; ifa = ifa->ifa_next) {
136 	if ((ifa->ifa_flags & IFF_UP) == 0)
137 	    continue;
138 	if (memcmp(ifa->ifa_addr, &sa_zero, sizeof(sa_zero)) == 0)
139 	    continue;
140 	if (krb5_sockaddr_uninteresting(ifa->ifa_addr))
141 	    continue;
142 
143 	if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) {
144 	    /* We'll deal with the LOOP_IF_NONE case later. */
145 	    if ((flags & LOOP) == 0)
146 		continue;
147 	}
148 
149 	ret = krb5_sockaddr2address(context, ifa->ifa_addr, &res->val[idx]);
150 	if (ret) {
151 	    /*
152 	     * The most likely error here is going to be "Program
153 	     * lacks support for address type".  This is no big
154 	     * deal -- just continue, and we'll listen on the
155 	     * addresses who's type we *do* support.
156 	     */
157 	    continue;
158 	}
159 	idx++;
160     }
161 
162     /*
163      * If no addresses were found, and LOOP_IF_NONE is set, then find
164      * the loopback addresses and add them to our list.
165      */
166     if ((flags & LOOP_IF_NONE) != 0 && idx == 0) {
167 	for (ifa = ifa0; ifa != NULL; ifa = ifa->ifa_next) {
168 	    if ((ifa->ifa_flags & IFF_UP) == 0)
169 		continue;
170 	    if (memcmp(ifa->ifa_addr, &sa_zero, sizeof(sa_zero)) == 0)
171 		continue;
172 	    if (krb5_sockaddr_uninteresting(ifa->ifa_addr))
173 		continue;
174 
175 	    if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) {
176 		ret = krb5_sockaddr2address(context,
177 					    ifa->ifa_addr, &res->val[idx]);
178 		if (ret) {
179 		    /*
180 		     * See comment above.
181 		     */
182 		    continue;
183 		}
184 		idx++;
185 	    }
186 	}
187     }
188 
189     freeifaddrs(ifa0);
190     if (ret)
191 	free(res->val);
192     else
193 	res->len = idx;        /* Now a count. */
194     return (ret);
195 }
196 
197 static krb5_error_code
198 get_addrs_int (krb5_context context, krb5_addresses *res, int flags)
199 {
200     krb5_error_code ret = -1;
201 
202     if (flags & SCAN_INTERFACES) {
203 	ret = find_all_addresses (context, res, flags);
204 	if(ret || res->len == 0)
205 	    ret = gethostname_fallback (context, res);
206     } else
207 	ret = 0;
208 
209     if(ret == 0 && (flags & EXTRA_ADDRESSES)) {
210 	/* append user specified addresses */
211 	krb5_addresses a;
212 	ret = krb5_get_extra_addresses(context, &a);
213 	if(ret) {
214 	    krb5_free_addresses(context, res);
215 	    return ret;
216 	}
217 	ret = krb5_append_addresses(context, res, &a);
218 	if(ret) {
219 	    krb5_free_addresses(context, res);
220 	    return ret;
221 	}
222 	krb5_free_addresses(context, &a);
223     }
224     return ret;
225 }
226 
227 /*
228  * Try to get all addresses, but return the one corresponding to
229  * `hostname' if we fail.
230  *
231  * Only include loopback address if there are no other.
232  */
233 
234 krb5_error_code
235 krb5_get_all_client_addrs (krb5_context context, krb5_addresses *res)
236 {
237     int flags = LOOP_IF_NONE | EXTRA_ADDRESSES;
238 
239     if (context->scan_interfaces)
240 	flags |= SCAN_INTERFACES;
241 
242     return get_addrs_int (context, res, flags);
243 }
244 
245 /*
246  * Try to get all local addresses that a server should listen to.
247  * If that fails, we return the address corresponding to `hostname'.
248  */
249 
250 krb5_error_code
251 krb5_get_all_server_addrs (krb5_context context, krb5_addresses *res)
252 {
253     return get_addrs_int (context, res, LOOP | SCAN_INTERFACES);
254 }
255