1 /*-
2 * Copyright (c) 2000 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Frank van der Linden.
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 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
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 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the NetBSD
19 * Foundation, Inc. and its contributors.
20 * 4. Neither the name of The NetBSD Foundation nor the names of its
21 * contributors may be used to endorse or promote products derived
22 * from this software without specific prior written permission.
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 * $NetBSD: util.c,v 1.4 2000/08/03 00:04:30 fvdl Exp $
37 * $FreeBSD: src/usr.sbin/rpcbind/util.c,v 1.6 2007/11/07 10:53:39 kevlo Exp $
38 */
39
40 #include <sys/types.h>
41 #include <sys/socket.h>
42 #include <sys/queue.h>
43 #include <net/if.h>
44 #include <netinet/in.h>
45 #include <ifaddrs.h>
46 #include <sys/poll.h>
47 #include <rpc/rpc.h>
48 #include <errno.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <netdb.h>
53 #include <netconfig.h>
54 #include <stdio.h>
55 #include <arpa/inet.h>
56
57 #include "rpcbind.h"
58
59 #define SA2SIN(sa) ((struct sockaddr_in *)(sa))
60 #define SA2SINADDR(sa) (SA2SIN(sa)->sin_addr)
61 #ifdef INET6
62 #define SA2SIN6(sa) ((struct sockaddr_in6 *)(sa))
63 #define SA2SIN6ADDR(sa) (SA2SIN6(sa)->sin6_addr)
64 #endif
65
66 static struct sockaddr_in *local_in4;
67 #ifdef INET6
68 static struct sockaddr_in6 *local_in6;
69 #endif
70
71 static int bitmaskcmp(void *, void *, void *, int);
72 #ifdef INET6
73 static void in6_fillscopeid(struct sockaddr_in6 *);
74 #endif
75
76 /*
77 * For all bits set in "mask", compare the corresponding bits in
78 * "dst" and "src", and see if they match. Returns 0 if the addresses
79 * match.
80 */
81 static int
bitmaskcmp(void * dst,void * src,void * mask,int bytelen)82 bitmaskcmp(void *dst, void *src, void *mask, int bytelen)
83 {
84 int i;
85 u_int8_t *p1 = dst, *p2 = src, *netmask = mask;
86
87 for (i = 0; i < bytelen; i++)
88 if ((p1[i] & netmask[i]) != (p2[i] & netmask[i]))
89 return (1);
90 return (0);
91 }
92
93 /*
94 * Similar to code in ifconfig.c. Fill in the scope ID for link-local
95 * addresses returned by getifaddrs().
96 */
97 #ifdef INET6
98 static void
in6_fillscopeid(struct sockaddr_in6 * sin6)99 in6_fillscopeid(struct sockaddr_in6 *sin6)
100 {
101 u_int16_t ifindex;
102
103 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
104 ifindex = ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]);
105 if (sin6->sin6_scope_id == 0 && ifindex != 0) {
106 sin6->sin6_scope_id = ifindex;
107 *(u_int16_t *)&sin6->sin6_addr.s6_addr[2] = 0;
108 }
109 }
110 }
111 #endif
112
113 /*
114 * Find a server address that can be used by `caller' to contact
115 * the local service specified by `serv_uaddr'. If `clnt_uaddr' is
116 * non-NULL, it is used instead of `caller' as a hint suggesting
117 * the best address (e.g. the `r_addr' field of an rpc, which
118 * contains the rpcbind server address that the caller used).
119 *
120 * Returns the best server address as a malloc'd "universal address"
121 * string which should be freed by the caller. On error, returns NULL.
122 */
123 char *
addrmerge(struct netbuf * caller,char * serv_uaddr,char * clnt_uaddr,char * netid)124 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
125 char *netid)
126 {
127 struct ifaddrs *ifap, *ifp = NULL, *bestif;
128 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf;
129 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa;
130 struct sockaddr_storage ss;
131 struct netconfig *nconf;
132 char *caller_uaddr = NULL, *hint_uaddr = NULL;
133 char *ret = NULL;
134
135 #ifdef ND_DEBUG
136 if (debugging)
137 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr,
138 clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid);
139 #endif
140 caller_sa = caller->buf;
141 if ((nconf = rpcbind_get_conf(netid)) == NULL)
142 goto freeit;
143 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL)
144 goto freeit;
145
146 /*
147 * Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its
148 * address family is different from that of the caller.
149 */
150 hint_sa = NULL;
151 if (clnt_uaddr != NULL) {
152 hint_uaddr = clnt_uaddr;
153 if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL)
154 goto freeit;
155 hint_sa = hint_nbp->buf;
156 }
157 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) {
158 hint_uaddr = caller_uaddr;
159 hint_sa = caller->buf;
160 }
161
162 #ifdef ND_DEBUG
163 if (debugging)
164 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr);
165 #endif
166 /* Local caller, just return the server address. */
167 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 ||
168 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') {
169 ret = strdup(serv_uaddr);
170 goto freeit;
171 }
172
173 if (getifaddrs(&ifp) < 0)
174 goto freeit;
175
176 /*
177 * Loop through all interfaces. For each interface, see if the
178 * network portion of its address is equal to that of the client.
179 * If so, we have found the interface that we want to use.
180 */
181 bestif = NULL;
182 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
183 ifsa = ifap->ifa_addr;
184 ifmasksa = ifap->ifa_netmask;
185
186 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family ||
187 !(ifap->ifa_flags & IFF_UP))
188 continue;
189
190 switch (hint_sa->sa_family) {
191 case AF_INET:
192 /*
193 * If the hint address matches this interface
194 * address/netmask, then we're done.
195 */
196 if (!bitmaskcmp(&SA2SINADDR(ifsa),
197 &SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa),
198 sizeof(struct in_addr))) {
199 bestif = ifap;
200 goto found;
201 }
202 break;
203 #ifdef INET6
204 case AF_INET6:
205 /*
206 * For v6 link local addresses, if the caller is on
207 * a link-local address then use the scope id to see
208 * which one.
209 */
210 in6_fillscopeid(SA2SIN6(ifsa));
211 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) &&
212 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) &&
213 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) {
214 if (SA2SIN6(ifsa)->sin6_scope_id ==
215 SA2SIN6(caller_sa)->sin6_scope_id) {
216 bestif = ifap;
217 goto found;
218 }
219 } else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa),
220 &SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa),
221 sizeof(struct in6_addr))) {
222 bestif = ifap;
223 goto found;
224 }
225 break;
226 #endif
227 default:
228 continue;
229 }
230
231 /*
232 * Remember the first possibly useful interface, preferring
233 * "normal" to point-to-point and loopback ones.
234 */
235 if (bestif == NULL ||
236 (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) &&
237 (bestif->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))))
238 bestif = ifap;
239 }
240 if (bestif == NULL)
241 goto freeit;
242
243 found:
244 /*
245 * Construct the new address using the the address from
246 * `bestif', and the port number from `serv_uaddr'.
247 */
248 serv_nbp = uaddr2taddr(nconf, serv_uaddr);
249 if (serv_nbp == NULL)
250 goto freeit;
251 serv_sa = serv_nbp->buf;
252
253 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len);
254 switch (ss.ss_family) {
255 case AF_INET:
256 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port;
257 break;
258 #ifdef INET6
259 case AF_INET6:
260 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port;
261 break;
262 #endif
263 }
264 tbuf.len = ss.ss_len;
265 tbuf.maxlen = sizeof(ss);
266 tbuf.buf = &ss;
267 ret = taddr2uaddr(nconf, &tbuf);
268
269 freeit:
270 if (caller_uaddr != NULL)
271 free(caller_uaddr);
272 if (hint_nbp != NULL) {
273 free(hint_nbp->buf);
274 free(hint_nbp);
275 }
276 if (serv_nbp != NULL) {
277 free(serv_nbp->buf);
278 free(serv_nbp);
279 }
280 if (ifp != NULL)
281 freeifaddrs(ifp);
282
283 #ifdef ND_DEBUG
284 if (debugging)
285 fprintf(stderr, "addrmerge: returning %s\n", ret);
286 #endif
287 return ret;
288 }
289
290 void
network_init(void)291 network_init(void)
292 {
293 #ifdef INET6
294 struct ifaddrs *ifap, *ifp;
295 struct ipv6_mreq mreq6;
296 unsigned int ifindex;
297 int s;
298 #endif
299 int ecode;
300 struct addrinfo hints, *res;
301
302 memset(&hints, 0, sizeof hints);
303 hints.ai_family = AF_INET;
304 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
305 if (debugging)
306 fprintf(stderr, "can't get local ip4 address: %s\n",
307 gai_strerror(ecode));
308 } else {
309 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4);
310 if (local_in4 == NULL) {
311 if (debugging)
312 fprintf(stderr, "can't alloc local ip4 addr\n");
313 }
314 memcpy(local_in4, res->ai_addr, sizeof *local_in4);
315 }
316
317 #ifdef INET6
318 hints.ai_family = AF_INET6;
319 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
320 if (debugging)
321 fprintf(stderr, "can't get local ip6 address: %s\n",
322 gai_strerror(ecode));
323 } else {
324 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6);
325 if (local_in6 == NULL) {
326 if (debugging)
327 fprintf(stderr, "can't alloc local ip6 addr\n");
328 }
329 memcpy(local_in6, res->ai_addr, sizeof *local_in6);
330 }
331
332 /*
333 * Now join the RPC ipv6 multicast group on all interfaces.
334 */
335 if (getifaddrs(&ifp) < 0)
336 return;
337
338 mreq6.ipv6mr_interface = 0;
339 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr);
340
341 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
342
343 /*
344 * Loop through all interfaces. For each IPv6 multicast-capable
345 * interface, join the RPC multicast group on that interface.
346 */
347 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
348 if (ifap->ifa_addr->sa_family != AF_INET6 ||
349 !(ifap->ifa_flags & IFF_MULTICAST))
350 continue;
351 ifindex = if_nametoindex(ifap->ifa_name);
352 if (ifindex == mreq6.ipv6mr_interface)
353 /*
354 * Already did this one.
355 */
356 continue;
357 mreq6.ipv6mr_interface = ifindex;
358 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6,
359 sizeof mreq6) < 0)
360 if (debugging)
361 perror("setsockopt v6 multicast");
362 }
363 #endif
364
365 /* close(s); */
366 }
367
368 struct sockaddr *
local_sa(int af)369 local_sa(int af)
370 {
371 switch (af) {
372 case AF_INET:
373 return (struct sockaddr *)local_in4;
374 #ifdef INET6
375 case AF_INET6:
376 return (struct sockaddr *)local_in6;
377 #endif
378 default:
379 return NULL;
380 }
381 }
382