1 /* $NetBSD: util.c,v 1.16 2009/01/18 10:17:38 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Frank van der Linden. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 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 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/types.h> 33 #include <sys/socket.h> 34 #include <sys/queue.h> 35 #include <net/if.h> 36 #include <netinet/in.h> 37 #include <assert.h> 38 #include <ifaddrs.h> 39 #include <poll.h> 40 #include <rpc/rpc.h> 41 #include <errno.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 #include <netdb.h> 46 #include <netconfig.h> 47 #include <stdio.h> 48 #include <arpa/inet.h> 49 50 #include "rpcbind.h" 51 52 static struct sockaddr_in *local_in4; 53 #ifdef INET6 54 static struct sockaddr_in6 *local_in6; 55 #endif 56 57 static int bitmaskcmp(void *, void *, void *, int); 58 #ifdef INET6 59 static void in6_fillscopeid(struct sockaddr_in6 *); 60 #endif 61 62 /* 63 * For all bits set in "mask", compare the corresponding bits in 64 * "dst" and "src", and see if they match. 65 */ 66 static int 67 bitmaskcmp(void *dst, void *src, void *mask, int bytelen) 68 { 69 int i, j; 70 u_int8_t *p1 = dst, *p2 = src, *netmask = mask; 71 u_int8_t bitmask; 72 73 for (i = 0; i < bytelen; i++) { 74 for (j = 0; j < 8; j++) { 75 bitmask = 1 << j; 76 if (!(netmask[i] & bitmask)) 77 continue; 78 if ((p1[i] & bitmask) != (p2[i] & bitmask)) 79 return 1; 80 } 81 } 82 83 return 0; 84 } 85 86 /* 87 * Taken from ifconfig.c 88 */ 89 #ifdef INET6 90 static void 91 in6_fillscopeid(struct sockaddr_in6 *sin6) 92 { 93 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 94 sin6->sin6_scope_id = 95 ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]); 96 sin6->sin6_addr.s6_addr[2] = sin6->sin6_addr.s6_addr[3] = 0; 97 } 98 } 99 #endif 100 101 char * 102 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr, 103 char *netid) 104 { 105 struct ifaddrs *ifap, *ifp, *bestif; 106 #ifdef INET6 107 struct sockaddr_in6 *servsin6, *sin6mask, *clntsin6, *ifsin6, *realsin6; 108 struct sockaddr_in6 *newsin6; 109 #endif 110 struct sockaddr_in *servsin, *sinmask, *clntsin, *newsin, *ifsin; 111 struct netbuf *serv_nbp, *clnt_nbp = NULL, tbuf; 112 struct sockaddr *serv_sa; 113 struct sockaddr *clnt_sa; 114 struct sockaddr_storage ss; 115 struct netconfig *nconf; 116 struct sockaddr *clnt = caller->buf; 117 char *ret = NULL; 118 119 #ifdef INET6 120 servsin6 = ifsin6 = newsin6 = NULL; /* XXXGCC -Wuninitialized */ 121 #endif 122 servsin = newsin = NULL; /* XXXGCC -Wuninitialized */ 123 124 #ifdef RPCBIND_DEBUG 125 if (debugging) 126 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 127 clnt_uaddr, netid); 128 #endif 129 nconf = getnetconfigent(netid); 130 if (nconf == NULL) 131 return NULL; 132 133 /* 134 * Local merge, just return a duplicate. 135 */ 136 if (clnt_uaddr != NULL && strncmp(clnt_uaddr, "0.0.0.0.", 8) == 0) 137 return strdup(clnt_uaddr); 138 139 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 140 if (serv_nbp == NULL) 141 return NULL; 142 143 serv_sa = (struct sockaddr *)serv_nbp->buf; 144 if (clnt_uaddr != NULL) { 145 clnt_nbp = uaddr2taddr(nconf, clnt_uaddr); 146 if (clnt_nbp == NULL) { 147 free(serv_nbp); 148 return NULL; 149 } 150 clnt_sa = (struct sockaddr *)clnt_nbp->buf; 151 if (clnt_sa->sa_family == AF_LOCAL) { 152 free(serv_nbp); 153 free(clnt_nbp); 154 free(clnt_sa); 155 return strdup(serv_uaddr); 156 } 157 } else { 158 clnt_sa = (struct sockaddr *) 159 malloc(sizeof (struct sockaddr_storage)); 160 memcpy(clnt_sa, clnt, clnt->sa_len); 161 } 162 163 if (getifaddrs(&ifp) < 0) { 164 free(serv_nbp); 165 free(clnt_sa); 166 if (clnt_nbp != NULL) 167 free(clnt_nbp); 168 return 0; 169 } 170 171 /* 172 * Loop through all interfaces. For each interface, see if the 173 * network portion of its address is equal to that of the client. 174 * If so, we have found the interface that we want to use. 175 */ 176 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 177 if (ifap->ifa_addr->sa_family != clnt->sa_family || 178 !(ifap->ifa_flags & IFF_UP)) 179 continue; 180 181 switch (clnt->sa_family) { 182 case AF_INET: 183 /* 184 * realsin: address that recvfrom gave us. 185 * ifsin: address of interface being examined. 186 * clntsin: address that client want us to contact 187 * it on 188 * servsin: local address of RPC service. 189 * sinmask: netmask of this interface 190 * newsin: initially a copy of clntsin, eventually 191 * the merged address 192 */ 193 servsin = (struct sockaddr_in *)serv_sa; 194 clntsin = (struct sockaddr_in *)clnt_sa; 195 sinmask = (struct sockaddr_in *)ifap->ifa_netmask; 196 newsin = (struct sockaddr_in *)&ss; 197 ifsin = (struct sockaddr_in *)ifap->ifa_addr; 198 if (!bitmaskcmp(&ifsin->sin_addr, &clntsin->sin_addr, 199 &sinmask->sin_addr, sizeof (struct in_addr))) { 200 goto found; 201 } 202 break; 203 #ifdef INET6 204 case AF_INET6: 205 /* 206 * realsin6: address that recvfrom gave us. 207 * ifsin6: address of interface being examined. 208 * clntsin6: address that client want us to contact 209 * it on 210 * servsin6: local address of RPC service. 211 * sin6mask: netmask of this interface 212 * newsin6: initially a copy of clntsin, eventually 213 * the merged address 214 * 215 * For v6 link local addresses, if the client contacted 216 * us via a link-local address, and wants us to reply 217 * to one, use the scope id to see which one. 218 */ 219 realsin6 = (struct sockaddr_in6 *)clnt; 220 ifsin6 = (struct sockaddr_in6 *)ifap->ifa_addr; 221 in6_fillscopeid(ifsin6); 222 clntsin6 = (struct sockaddr_in6 *)clnt_sa; 223 servsin6 = (struct sockaddr_in6 *)serv_sa; 224 sin6mask = (struct sockaddr_in6 *)ifap->ifa_netmask; 225 newsin6 = (struct sockaddr_in6 *)&ss; 226 if (IN6_IS_ADDR_LINKLOCAL(&ifsin6->sin6_addr) && 227 IN6_IS_ADDR_LINKLOCAL(&realsin6->sin6_addr) && 228 IN6_IS_ADDR_LINKLOCAL(&clntsin6->sin6_addr)) { 229 if (ifsin6->sin6_scope_id != 230 realsin6->sin6_scope_id) 231 continue; 232 goto found; 233 } 234 if (!bitmaskcmp(&ifsin6->sin6_addr, 235 &clntsin6->sin6_addr, &sin6mask->sin6_addr, 236 sizeof (struct in6_addr))) 237 goto found; 238 break; 239 #endif 240 default: 241 goto freeit; 242 } 243 } 244 /* 245 * Didn't find anything. Get the first possibly useful interface, 246 * preferring "normal" interfaces to point-to-point and loopback 247 * ones. 248 */ 249 bestif = NULL; 250 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 251 if (ifap->ifa_addr->sa_family != clnt->sa_family || 252 !(ifap->ifa_flags & IFF_UP)) 253 continue; 254 if (!(ifap->ifa_flags & IFF_LOOPBACK) && 255 !(ifap->ifa_flags & IFF_POINTOPOINT)) { 256 bestif = ifap; 257 break; 258 } 259 if (bestif == NULL) 260 bestif = ifap; 261 else if ((bestif->ifa_flags & IFF_LOOPBACK) && 262 !(ifap->ifa_flags & IFF_LOOPBACK)) 263 bestif = ifap; 264 } 265 ifap = bestif; 266 found: 267 switch (clnt->sa_family) { 268 case AF_INET: 269 memcpy(newsin, ifap->ifa_addr, clnt_sa->sa_len); 270 newsin->sin_port = servsin->sin_port; 271 tbuf.len = clnt_sa->sa_len; 272 tbuf.maxlen = sizeof (struct sockaddr_storage); 273 tbuf.buf = newsin; 274 break; 275 #ifdef INET6 276 case AF_INET6: 277 assert(newsin6); 278 memcpy(newsin6, ifsin6, clnt_sa->sa_len); 279 newsin6->sin6_port = servsin6->sin6_port; 280 tbuf.maxlen = sizeof (struct sockaddr_storage); 281 tbuf.len = clnt_sa->sa_len; 282 tbuf.buf = newsin6; 283 break; 284 #endif 285 default: 286 goto freeit; 287 } 288 if (ifap != NULL) 289 ret = taddr2uaddr(nconf, &tbuf); 290 freeit: 291 freenetconfigent(nconf); 292 free(serv_sa); 293 free(serv_nbp); 294 if (clnt_sa != NULL) 295 free(clnt_sa); 296 if (clnt_nbp != NULL) 297 free(clnt_nbp); 298 freeifaddrs(ifp); 299 300 #ifdef RPCBIND_DEBUG 301 if (debugging) 302 fprintf(stderr, "addrmerge: returning %s\n", ret); 303 #endif 304 return ret; 305 } 306 307 void 308 network_init() 309 { 310 #ifdef INET6 311 struct ifaddrs *ifap, *ifp; 312 struct ipv6_mreq mreq6; 313 unsigned int ifindex; 314 int s; 315 #endif 316 int ecode; 317 struct addrinfo hints, *res; 318 319 memset(&hints, 0, sizeof hints); 320 hints.ai_family = AF_INET; 321 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 322 if (debugging) 323 fprintf(stderr, "can't get local ip4 address: %s\n", 324 gai_strerror(ecode)); 325 } else { 326 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 327 if (local_in4 == NULL) { 328 if (debugging) 329 fprintf(stderr, "can't alloc local ip4 addr\n"); 330 } 331 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 332 } 333 334 #ifdef INET6 335 hints.ai_family = AF_INET6; 336 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 337 if (debugging) 338 fprintf(stderr, "can't get local ip6 address: %s\n", 339 gai_strerror(ecode)); 340 } else { 341 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 342 if (local_in6 == NULL) { 343 if (debugging) 344 fprintf(stderr, "can't alloc local ip6 addr\n"); 345 } 346 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 347 } 348 349 /* 350 * Now join the RPC ipv6 multicast group on all interfaces. 351 */ 352 if (getifaddrs(&ifp) < 0) 353 return; 354 355 mreq6.ipv6mr_interface = 0; 356 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 357 358 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 359 360 /* 361 * Loop through all interfaces. For each interface, see if the 362 * network portion of its address is equal to that of the client. 363 * If so, we have found the interface that we want to use. 364 */ 365 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 366 if (ifap->ifa_addr->sa_family != AF_INET6 || 367 !(ifap->ifa_flags & IFF_MULTICAST)) 368 continue; 369 ifindex = if_nametoindex(ifap->ifa_name); 370 if (ifindex == mreq6.ipv6mr_interface) 371 /* 372 * Already did this one. 373 */ 374 continue; 375 mreq6.ipv6mr_interface = ifindex; 376 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 377 sizeof mreq6) < 0) 378 if (debugging) 379 perror("setsockopt v6 multicast"); 380 } 381 #endif 382 383 /* close(s); */ 384 } 385 386 struct sockaddr * 387 local_sa(int af) 388 { 389 switch (af) { 390 case AF_INET: 391 return (struct sockaddr *)local_in4; 392 #ifdef INET6 393 case AF_INET6: 394 return (struct sockaddr *)local_in6; 395 #endif 396 default: 397 return NULL; 398 } 399 } 400