1 /* $NetBSD: util.c,v 1.24 2020/06/17 00:16:22 kamil Exp $ */
2 /* $FreeBSD: head/usr.sbin/rpcbind/util.c 300973 2016-05-29 20:28:01Z ngie $ */
3
4 /*-
5 * Copyright (c) 2000 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Frank van der Linden.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <sys/queue.h>
36 #include <net/if.h>
37 #include <netinet/in.h>
38 #include <assert.h>
39 #include <ifaddrs.h>
40 #include <poll.h>
41 #include <rpc/rpc.h>
42 #include <errno.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <netdb.h>
47 #include <netconfig.h>
48 #include <stdio.h>
49 #include <arpa/inet.h>
50 #include <err.h>
51
52 #ifdef RPCBIND_RUMP
53 #include <rump/rump.h>
54 #include <rump/rump_syscallshotgun.h>
55 #include <rump/rump_syscalls.h>
56 #endif
57
58 #include "rpcbind.h"
59
60 static struct sockaddr_in *local_in4;
61 #ifdef INET6
62 static struct sockaddr_in6 *local_in6;
63 #endif
64
65 static int bitmaskcmp(void *, void *, void *, int);
66
67 /*
68 * For all bits set in "mask", compare the corresponding bits in
69 * "dst" and "src", and see if they match. Returns 0 if the addresses
70 * match.
71 */
72 static int
bitmaskcmp(void * dst,void * src,void * mask,int bytelen)73 bitmaskcmp(void *dst, void *src, void *mask, int bytelen)
74 {
75 int i, j;
76 u_int8_t *p1 = dst, *p2 = src, *netmask = mask;
77 u_int8_t bitmask;
78
79 for (i = 0; i < bytelen; i++) {
80 for (j = 0; j < 8; j++) {
81 bitmask = 1 << j;
82 if (!(netmask[i] & bitmask))
83 continue;
84 if ((p1[i] & bitmask) != (p2[i] & bitmask))
85 return 1;
86 }
87 }
88
89 return 0;
90 }
91
92 char *
addrmerge(struct netbuf * caller,char * serv_uaddr,char * clnt_uaddr,const char * netid)93 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
94 const char *netid)
95 {
96 struct ifaddrs *ifap, *ifp, *bestif;
97 #ifdef INET6
98 struct sockaddr_in6 *servsin6, *sin6mask, *clntsin6, *ifsin6, *realsin6;
99 struct sockaddr_in6 *newsin6;
100 #endif
101 struct sockaddr_in *servsin, *sinmask, *clntsin, *newsin, *ifsin;
102 struct netbuf *serv_nbp, *clnt_nbp = NULL, tbuf;
103 struct sockaddr *serv_sa;
104 struct sockaddr *clnt_sa;
105 struct sockaddr_storage ss;
106 struct netconfig *nconf;
107 struct sockaddr *clnt = caller->buf;
108 char *ret = NULL;
109
110 #ifdef INET6
111 servsin6 = ifsin6 = newsin6 = NULL; /* XXXGCC -Wuninitialized */
112 #endif
113 servsin = newsin = NULL; /* XXXGCC -Wuninitialized */
114
115 #ifdef RPCBIND_DEBUG
116 if (debugging)
117 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr,
118 clnt_uaddr, netid);
119 #endif
120 nconf = getnetconfigent(netid);
121 if (nconf == NULL)
122 return NULL;
123
124 /*
125 * Local merge, just return a duplicate.
126 */
127 if (clnt_uaddr != NULL && strncmp(clnt_uaddr, "0.0.0.0.", 8) == 0)
128 return strdup(clnt_uaddr);
129
130 serv_nbp = uaddr2taddr(nconf, serv_uaddr);
131 if (serv_nbp == NULL)
132 return NULL;
133
134 serv_sa = serv_nbp->buf;
135 if (clnt_uaddr != NULL) {
136 clnt_nbp = uaddr2taddr(nconf, clnt_uaddr);
137 if (clnt_nbp == NULL) {
138 free(serv_nbp);
139 return NULL;
140 }
141 clnt_sa = clnt_nbp->buf;
142 if (clnt_sa->sa_family == AF_LOCAL) {
143 free(serv_nbp);
144 free(clnt_nbp);
145 free(clnt_sa);
146 return strdup(serv_uaddr);
147 }
148 } else {
149 clnt_sa = malloc(clnt->sa_len);
150 if (clnt_sa == NULL) {
151 free(serv_nbp);
152 return NULL;
153 }
154 memcpy(clnt_sa, clnt, clnt->sa_len);
155 }
156
157 if (getifaddrs(&ifp) < 0) {
158 free(serv_nbp);
159 free(clnt_sa);
160 if (clnt_nbp != NULL)
161 free(clnt_nbp);
162 return 0;
163 }
164
165 /*
166 * Loop through all interfaces. For each interface, see if the
167 * network portion of its address is equal to that of the client.
168 * If so, we have found the interface that we want to use.
169 */
170 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
171 if (ifap->ifa_addr->sa_family != clnt->sa_family ||
172 !(ifap->ifa_flags & IFF_UP))
173 continue;
174
175 switch (clnt->sa_family) {
176 case AF_INET:
177 /*
178 * realsin: address that recvfrom gave us.
179 * ifsin: address of interface being examined.
180 * clntsin: address that client want us to contact
181 * it on
182 * servsin: local address of RPC service.
183 * sinmask: netmask of this interface
184 * newsin: initially a copy of clntsin, eventually
185 * the merged address
186 */
187 servsin = (struct sockaddr_in *)serv_sa;
188 clntsin = (struct sockaddr_in *)clnt_sa;
189 sinmask = (struct sockaddr_in *)ifap->ifa_netmask;
190 newsin = (struct sockaddr_in *)&ss;
191 ifsin = (struct sockaddr_in *)ifap->ifa_addr;
192 if (!bitmaskcmp(&ifsin->sin_addr, &clntsin->sin_addr,
193 &sinmask->sin_addr, sizeof (struct in_addr))) {
194 goto found;
195 }
196 break;
197 #ifdef INET6
198 case AF_INET6:
199 /*
200 * realsin6: address that recvfrom gave us.
201 * ifsin6: address of interface being examined.
202 * clntsin6: address that client want us to contact
203 * it on
204 * servsin6: local address of RPC service.
205 * sin6mask: netmask of this interface
206 * newsin6: initially a copy of clntsin, eventually
207 * the merged address
208 *
209 * For v6 link local addresses, if the client contacted
210 * us via a link-local address, and wants us to reply
211 * to one, use the scope id to see which one.
212 */
213 realsin6 = (struct sockaddr_in6 *)clnt;
214 ifsin6 = (struct sockaddr_in6 *)ifap->ifa_addr;
215 inet6_getscopeid(ifsin6, 1);
216 clntsin6 = (struct sockaddr_in6 *)clnt_sa;
217 servsin6 = (struct sockaddr_in6 *)serv_sa;
218 sin6mask = (struct sockaddr_in6 *)ifap->ifa_netmask;
219 newsin6 = (struct sockaddr_in6 *)&ss;
220 if (IN6_IS_ADDR_LINKLOCAL(&ifsin6->sin6_addr) &&
221 IN6_IS_ADDR_LINKLOCAL(&realsin6->sin6_addr) &&
222 IN6_IS_ADDR_LINKLOCAL(&clntsin6->sin6_addr)) {
223 if (ifsin6->sin6_scope_id !=
224 realsin6->sin6_scope_id)
225 continue;
226 goto found;
227 }
228 if (!bitmaskcmp(&ifsin6->sin6_addr,
229 &clntsin6->sin6_addr, &sin6mask->sin6_addr,
230 sizeof (struct in6_addr)))
231 goto found;
232 break;
233 #endif
234 default:
235 goto freeit;
236 }
237 }
238 /*
239 * Didn't find anything. Get the first possibly useful interface,
240 * preferring "normal" interfaces to point-to-point and loopback
241 * ones.
242 */
243 bestif = NULL;
244 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
245 if (ifap->ifa_addr->sa_family != clnt->sa_family ||
246 !(ifap->ifa_flags & IFF_UP))
247 continue;
248 if (!(ifap->ifa_flags & IFF_LOOPBACK) &&
249 !(ifap->ifa_flags & IFF_POINTOPOINT)) {
250 bestif = ifap;
251 break;
252 }
253 if (bestif == NULL)
254 bestif = ifap;
255 else if ((bestif->ifa_flags & IFF_LOOPBACK) &&
256 !(ifap->ifa_flags & IFF_LOOPBACK))
257 bestif = ifap;
258 }
259 ifap = bestif;
260 found:
261 switch (clnt->sa_family) {
262 case AF_INET:
263 memcpy(newsin, ifap->ifa_addr, clnt_sa->sa_len);
264 newsin->sin_port = servsin->sin_port;
265 tbuf.len = clnt_sa->sa_len;
266 tbuf.maxlen = sizeof (struct sockaddr_storage);
267 tbuf.buf = newsin;
268 break;
269 #ifdef INET6
270 case AF_INET6:
271 memcpy(newsin6, ifsin6, clnt_sa->sa_len);
272 newsin6->sin6_port = servsin6->sin6_port;
273 tbuf.maxlen = sizeof (struct sockaddr_storage);
274 tbuf.len = clnt_sa->sa_len;
275 tbuf.buf = newsin6;
276 break;
277 #endif
278 default:
279 goto freeit;
280 }
281 if (ifap != NULL)
282 ret = taddr2uaddr(nconf, &tbuf);
283 freeit:
284 freenetconfigent(nconf);
285 free(serv_sa);
286 free(serv_nbp);
287 if (clnt_sa != NULL)
288 free(clnt_sa);
289 if (clnt_nbp != NULL)
290 free(clnt_nbp);
291 freeifaddrs(ifp);
292
293 #ifdef RPCBIND_DEBUG
294 if (debugging)
295 fprintf(stderr, "addrmerge: returning %s\n", ret);
296 #endif
297 return ret;
298 }
299
300 void
network_init()301 network_init()
302 {
303 #ifdef INET6
304 struct ifaddrs *ifap, *ifp;
305 struct ipv6_mreq mreq6;
306 unsigned int ifindex;
307 int s;
308 #endif
309 int ecode;
310 struct addrinfo hints, *res;
311
312 memset(&hints, 0, sizeof hints);
313 hints.ai_family = AF_INET;
314 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
315 if (debugging)
316 fprintf(stderr, "can't get local ip4 address: %s\n",
317 gai_strerror(ecode));
318 } else {
319 local_in4 = malloc(sizeof(*local_in4));
320 if (local_in4 == NULL) {
321 if (debugging)
322 fprintf(stderr, "can't alloc local ip4 addr\n");
323 }
324 memcpy(local_in4, res->ai_addr, sizeof *local_in4);
325 }
326
327 #ifdef INET6
328 hints.ai_family = AF_INET6;
329 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
330 if (debugging)
331 fprintf(stderr, "can't get local ip6 address: %s\n",
332 gai_strerror(ecode));
333 } else {
334 local_in6 = malloc(sizeof(*local_in6));
335 if (local_in6 == NULL) {
336 if (debugging)
337 fprintf(stderr, "can't alloc local ip6 addr\n");
338 }
339 memcpy(local_in6, res->ai_addr, sizeof *local_in6);
340 }
341
342 /*
343 * Now join the RPC ipv6 multicast group on all interfaces.
344 */
345 if (getifaddrs(&ifp) < 0)
346 return;
347
348 mreq6.ipv6mr_interface = 0;
349 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr);
350
351 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
352
353 /*
354 * Loop through all interfaces. For each interface, see if the
355 * network portion of its address is equal to that of the client.
356 * If so, we have found the interface that we want to use.
357 */
358 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
359 if (ifap->ifa_addr->sa_family != AF_INET6 ||
360 !(ifap->ifa_flags & IFF_MULTICAST))
361 continue;
362 ifindex = if_nametoindex(ifap->ifa_name);
363 if (ifindex == mreq6.ipv6mr_interface)
364 /*
365 * Already did this one.
366 */
367 continue;
368 mreq6.ipv6mr_interface = ifindex;
369 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6,
370 sizeof mreq6) < 0)
371 if (debugging)
372 warn("setsockopt v6 multicast");
373 }
374 freeifaddrs(ifp);
375 #endif
376
377 /* close(s); */
378 }
379
380 struct sockaddr *
local_sa(int af)381 local_sa(int af)
382 {
383 switch (af) {
384 case AF_INET:
385 return (struct sockaddr *)local_in4;
386 #ifdef INET6
387 case AF_INET6:
388 return (struct sockaddr *)local_in6;
389 #endif
390 default:
391 return NULL;
392 }
393 }
394