1/* $NetBSD: get_addrs.c,v 1.2 2017/01/28 21:31:49 christos Exp $ */
2
3/*
4 * Copyright (c) 1997 - 2002 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#ifdef __osf__
39/* hate */
40struct rtentry;
41struct mbuf;
42#endif
43#ifdef HAVE_NET_IF_H
44#include <net/if.h>
45#endif
46#include <ifaddrs.h>
47
48static krb5_error_code
49gethostname_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_message(context, ret, "gethostname: %s", strerror(ret));
58 return ret;
59 }
60 hostent = roken_gethostbyname (hostname);
61 if (hostent == NULL) {
62 ret = errno;
63 krb5_set_error_message (context, ret, "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 return krb5_enomem(context);
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
84enum {
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
96static krb5_error_code
97find_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 if (flags & EXTRA_ADDRESSES)
134 krb5_free_addresses(context, &ignore_addresses);
135 freeifaddrs(ifa0);
136 return krb5_enomem(context);
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
220static krb5_error_code
221get_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
265KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
266krb5_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
281KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
282krb5_get_all_server_addrs (krb5_context context, krb5_addresses *res)
283{
284 return get_addrs_int (context, res, LOOP | SCAN_INTERFACES);
285}
286