1 /*
2 * $NetBSD: util.c,v 1.4 2000/08/03 00:04:30 fvdl Exp $
3 * $FreeBSD$
4 */
5
6 /*-
7 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
8 *
9 * Copyright (c) 2000 The NetBSD Foundation, Inc.
10 * All rights reserved.
11 *
12 * This code is derived from software contributed to The NetBSD Foundation
13 * by Frank van der Linden.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
28 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include <sys/types.h>
38 #include <sys/socket.h>
39 #include <sys/queue.h>
40 #include <net/if.h>
41 #include <netinet/in.h>
42 #include <ifaddrs.h>
43 #include <sys/poll.h>
44 #include <rpc/rpc.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <netdb.h>
48 #include <netconfig.h>
49 #include <stdio.h>
50 #include <arpa/inet.h>
51
52 #include "rpcbind.h"
53
54 static struct sockaddr_in *local_in4;
55 #ifdef INET6
56 static struct sockaddr_in6 *local_in6;
57 #endif
58
59 static int bitmaskcmp(struct sockaddr *, struct sockaddr *, struct sockaddr *);
60
61 /*
62 * For all bits set in "mask", compare the corresponding bits in
63 * "dst" and "src", and see if they match. Returns 0 if the addresses
64 * match.
65 */
66 static int
bitmaskcmp(struct sockaddr * dst,struct sockaddr * src,struct sockaddr * mask)67 bitmaskcmp(struct sockaddr *dst, struct sockaddr *src, struct sockaddr *mask)
68 {
69 int i;
70 u_int8_t *p1, *p2, *netmask;
71 int bytelen;
72
73 if (dst->sa_family != src->sa_family ||
74 dst->sa_family != mask->sa_family)
75 return (1);
76
77 switch (dst->sa_family) {
78 case AF_INET:
79 p1 = (uint8_t*) &SA2SINADDR(dst);
80 p2 = (uint8_t*) &SA2SINADDR(src);
81 netmask = (uint8_t*) &SA2SINADDR(mask);
82 bytelen = sizeof(struct in_addr);
83 break;
84 #ifdef INET6
85 case AF_INET6:
86 p1 = (uint8_t*) &SA2SIN6ADDR(dst);
87 p2 = (uint8_t*) &SA2SIN6ADDR(src);
88 netmask = (uint8_t*) &SA2SIN6ADDR(mask);
89 bytelen = sizeof(struct in6_addr);
90 break;
91 #endif
92 default:
93 return (1);
94 }
95
96 for (i = 0; i < bytelen; i++)
97 if ((p1[i] & netmask[i]) != (p2[i] & netmask[i]))
98 return (1);
99 return (0);
100 }
101
102 /*
103 * Find a server address that can be used by `caller' to contact
104 * the local service specified by `serv_uaddr'. If `clnt_uaddr' is
105 * non-NULL, it is used instead of `caller' as a hint suggesting
106 * the best address (e.g. the `r_addr' field of an rpc, which
107 * contains the rpcbind server address that the caller used).
108 *
109 * Returns the best server address as a malloc'd "universal address"
110 * string which should be freed by the caller. On error, returns NULL.
111 */
112 char *
addrmerge(struct netbuf * caller,const char * serv_uaddr,const char * clnt_uaddr,const char * netid)113 addrmerge(struct netbuf *caller, const char *serv_uaddr, const char *clnt_uaddr,
114 const char *netid)
115 {
116 struct ifaddrs *ifap, *ifp = NULL, *bestif;
117 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf;
118 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa;
119 struct sockaddr_storage ss;
120 struct netconfig *nconf;
121 char *caller_uaddr = NULL;
122 #ifdef ND_DEBUG
123 const char *hint_uaddr = NULL;
124 #endif
125 char *ret = NULL;
126 int bestif_goodness;
127
128 #ifdef ND_DEBUG
129 if (debugging)
130 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr,
131 clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid);
132 #endif
133 caller_sa = caller->buf;
134 if ((nconf = rpcbind_get_conf(netid)) == NULL)
135 goto freeit;
136 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL)
137 goto freeit;
138
139 /*
140 * Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its
141 * address family is different from that of the caller.
142 */
143 hint_sa = NULL;
144 if (clnt_uaddr != NULL) {
145 #ifdef ND_DEBUG
146 hint_uaddr = clnt_uaddr;
147 #endif
148 if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL)
149 goto freeit;
150 hint_sa = hint_nbp->buf;
151 }
152 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) {
153 #ifdef ND_DEBUG
154 hint_uaddr = caller_uaddr;
155 #endif
156 hint_sa = caller->buf;
157 }
158
159 #ifdef ND_DEBUG
160 if (debugging)
161 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr);
162 #endif
163 /* Local caller, just return the server address. */
164 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 ||
165 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') {
166 ret = strdup(serv_uaddr);
167 goto freeit;
168 }
169
170 if (getifaddrs(&ifp) < 0)
171 goto freeit;
172
173 /*
174 * Loop through all interface addresses. We are listening to an address
175 * if any of the following are true:
176 * a) It's a loopback address
177 * b) It was specified with the -h command line option
178 * c) There were no -h command line options.
179 *
180 * Among addresses on which we are listening, choose in order of
181 * preference an address that is:
182 *
183 * a) Equal to the hint
184 * b) A link local address with the same scope ID as the client's
185 * address, if the client's address is also link local
186 * c) An address on the same subnet as the client's address
187 * d) A non-localhost, non-p2p address
188 * e) Any usable address
189 */
190 bestif = NULL;
191 bestif_goodness = 0;
192 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
193 ifsa = ifap->ifa_addr;
194 ifmasksa = ifap->ifa_netmask;
195
196 /* Skip addresses where we don't listen */
197 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family ||
198 !(ifap->ifa_flags & IFF_UP))
199 continue;
200
201 if (!(ifap->ifa_flags & IFF_LOOPBACK) && !listen_addr(ifsa))
202 continue;
203
204 if ((hint_sa->sa_family == AF_INET) &&
205 ((((struct sockaddr_in*)hint_sa)->sin_addr.s_addr ==
206 ((struct sockaddr_in*)ifsa)->sin_addr.s_addr))) {
207 const int goodness = 4;
208
209 bestif_goodness = goodness;
210 bestif = ifap;
211 goto found;
212 }
213 #ifdef INET6
214 if ((hint_sa->sa_family == AF_INET6) &&
215 (0 == memcmp(&((struct sockaddr_in6*)hint_sa)->sin6_addr,
216 &((struct sockaddr_in6*)ifsa)->sin6_addr,
217 sizeof(struct in6_addr))) &&
218 (((struct sockaddr_in6*)hint_sa)->sin6_scope_id ==
219 (((struct sockaddr_in6*)ifsa)->sin6_scope_id))) {
220 const int goodness = 4;
221
222 bestif_goodness = goodness;
223 bestif = ifap;
224 goto found;
225 }
226 if (hint_sa->sa_family == AF_INET6) {
227 /*
228 * For v6 link local addresses, if the caller is on
229 * a link-local address then use the scope id to see
230 * which one.
231 */
232 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa))) {
233 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) &&
234 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa)) &&
235 (SA2SIN6(ifsa)->sin6_scope_id ==
236 SA2SIN6(caller_sa)->sin6_scope_id)) {
237 const int goodness = 3;
238
239 if (bestif_goodness < goodness) {
240 bestif = ifap;
241 bestif_goodness = goodness;
242 }
243 } else {
244 continue;
245 }
246 }
247 }
248 #endif /* INET6 */
249 if (0 == bitmaskcmp(hint_sa, ifsa, ifmasksa)) {
250 const int goodness = 2;
251
252 if (bestif_goodness < goodness) {
253 bestif = ifap;
254 bestif_goodness = goodness;
255 }
256 }
257 if (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
258 const int goodness = 1;
259
260 if (bestif_goodness < goodness) {
261 bestif = ifap;
262 bestif_goodness = goodness;
263 }
264 }
265 if (bestif == NULL)
266 bestif = ifap;
267 }
268 if (bestif == NULL)
269 goto freeit;
270
271 found:
272 /*
273 * Construct the new address using the address from
274 * `bestif', and the port number from `serv_uaddr'.
275 */
276 serv_nbp = uaddr2taddr(nconf, serv_uaddr);
277 if (serv_nbp == NULL)
278 goto freeit;
279 serv_sa = serv_nbp->buf;
280
281 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len);
282 switch (ss.ss_family) {
283 case AF_INET:
284 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port;
285 break;
286 #ifdef INET6
287 case AF_INET6:
288 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port;
289 break;
290 #endif
291 }
292 tbuf.len = ss.ss_len;
293 tbuf.maxlen = sizeof(ss);
294 tbuf.buf = &ss;
295 ret = taddr2uaddr(nconf, &tbuf);
296
297 freeit:
298 free(caller_uaddr);
299 if (hint_nbp != NULL) {
300 free(hint_nbp->buf);
301 free(hint_nbp);
302 }
303 if (serv_nbp != NULL) {
304 free(serv_nbp->buf);
305 free(serv_nbp);
306 }
307 if (ifp != NULL)
308 freeifaddrs(ifp);
309
310 #ifdef ND_DEBUG
311 if (debugging)
312 fprintf(stderr, "addrmerge: returning %s\n", ret);
313 #endif
314 return ret;
315 }
316
317 void
network_init(void)318 network_init(void)
319 {
320 #ifdef INET6
321 struct ifaddrs *ifap, *ifp;
322 struct ipv6_mreq mreq6;
323 unsigned int ifindex;
324 int s;
325 #endif
326 int ecode;
327 struct addrinfo hints, *res;
328
329 memset(&hints, 0, sizeof hints);
330 hints.ai_family = AF_INET;
331 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
332 if (debugging)
333 fprintf(stderr, "can't get local ip4 address: %s\n",
334 gai_strerror(ecode));
335 } else {
336 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4);
337 if (local_in4 == NULL) {
338 if (debugging)
339 fprintf(stderr, "can't alloc local ip4 addr\n");
340 exit(1);
341 }
342 memcpy(local_in4, res->ai_addr, sizeof *local_in4);
343 freeaddrinfo(res);
344 }
345
346 #ifdef INET6
347 hints.ai_family = AF_INET6;
348 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
349 if (debugging)
350 fprintf(stderr, "can't get local ip6 address: %s\n",
351 gai_strerror(ecode));
352 } else {
353 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6);
354 if (local_in6 == NULL) {
355 if (debugging)
356 fprintf(stderr, "can't alloc local ip6 addr\n");
357 exit(1);
358 }
359 memcpy(local_in6, res->ai_addr, sizeof *local_in6);
360 freeaddrinfo(res);
361 }
362
363 /*
364 * Now join the RPC ipv6 multicast group on all interfaces.
365 */
366 if (getifaddrs(&ifp) < 0)
367 return;
368
369 mreq6.ipv6mr_interface = 0;
370 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr);
371
372 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
373 if (s == -1) {
374 if (debugging)
375 fprintf(stderr, "couldn't create ip6 socket");
376 goto done_inet6;
377 }
378
379 /*
380 * Loop through all interfaces. For each IPv6 multicast-capable
381 * interface, join the RPC multicast group on that interface.
382 */
383 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
384 if (ifap->ifa_addr->sa_family != AF_INET6 ||
385 !(ifap->ifa_flags & IFF_MULTICAST))
386 continue;
387 ifindex = if_nametoindex(ifap->ifa_name);
388 if (ifindex == mreq6.ipv6mr_interface)
389 /*
390 * Already did this one.
391 */
392 continue;
393 mreq6.ipv6mr_interface = ifindex;
394 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6,
395 sizeof mreq6) < 0)
396 if (debugging)
397 perror("setsockopt v6 multicast");
398 }
399 done_inet6:
400 freeifaddrs(ifp);
401 #endif
402
403 /* close(s); */
404 }
405
406 struct sockaddr *
local_sa(int af)407 local_sa(int af)
408 {
409 switch (af) {
410 case AF_INET:
411 return (struct sockaddr *)local_in4;
412 #ifdef INET6
413 case AF_INET6:
414 return (struct sockaddr *)local_in6;
415 #endif
416 default:
417 return NULL;
418 }
419 }
420