1 /* $NetBSD: util.c,v 1.21 2017/08/16 08:44:40 christos 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_syscalls.h> 55 #endif 56 57 #include "rpcbind.h" 58 59 static struct sockaddr_in *local_in4; 60 #ifdef INET6 61 static struct sockaddr_in6 *local_in6; 62 #endif 63 64 static int bitmaskcmp(void *, void *, void *, int); 65 66 /* 67 * For all bits set in "mask", compare the corresponding bits in 68 * "dst" and "src", and see if they match. Returns 0 if the addresses 69 * match. 70 */ 71 static int 72 bitmaskcmp(void *dst, void *src, void *mask, int bytelen) 73 { 74 int i, j; 75 u_int8_t *p1 = dst, *p2 = src, *netmask = mask; 76 u_int8_t bitmask; 77 78 for (i = 0; i < bytelen; i++) { 79 for (j = 0; j < 8; j++) { 80 bitmask = 1 << j; 81 if (!(netmask[i] & bitmask)) 82 continue; 83 if ((p1[i] & bitmask) != (p2[i] & bitmask)) 84 return 1; 85 } 86 } 87 88 return 0; 89 } 90 91 char * 92 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr, 93 const char *netid) 94 { 95 struct ifaddrs *ifap, *ifp, *bestif; 96 #ifdef INET6 97 struct sockaddr_in6 *servsin6, *sin6mask, *clntsin6, *ifsin6, *realsin6; 98 struct sockaddr_in6 *newsin6; 99 #endif 100 struct sockaddr_in *servsin, *sinmask, *clntsin, *newsin, *ifsin; 101 struct netbuf *serv_nbp, *clnt_nbp = NULL, tbuf; 102 struct sockaddr *serv_sa; 103 struct sockaddr *clnt_sa; 104 struct sockaddr_storage ss; 105 struct netconfig *nconf; 106 struct sockaddr *clnt = caller->buf; 107 char *ret = NULL; 108 109 #ifdef INET6 110 servsin6 = ifsin6 = newsin6 = NULL; /* XXXGCC -Wuninitialized */ 111 #endif 112 servsin = newsin = NULL; /* XXXGCC -Wuninitialized */ 113 114 #ifdef RPCBIND_DEBUG 115 if (debugging) 116 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 117 clnt_uaddr, netid); 118 #endif 119 nconf = getnetconfigent(netid); 120 if (nconf == NULL) 121 return NULL; 122 123 /* 124 * Local merge, just return a duplicate. 125 */ 126 if (clnt_uaddr != NULL && strncmp(clnt_uaddr, "0.0.0.0.", 8) == 0) 127 return strdup(clnt_uaddr); 128 129 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 130 if (serv_nbp == NULL) 131 return NULL; 132 133 serv_sa = (struct sockaddr *)serv_nbp->buf; 134 if (clnt_uaddr != NULL) { 135 clnt_nbp = uaddr2taddr(nconf, clnt_uaddr); 136 if (clnt_nbp == NULL) { 137 free(serv_nbp); 138 return NULL; 139 } 140 clnt_sa = (struct sockaddr *)clnt_nbp->buf; 141 if (clnt_sa->sa_family == AF_LOCAL) { 142 free(serv_nbp); 143 free(clnt_nbp); 144 free(clnt_sa); 145 return strdup(serv_uaddr); 146 } 147 } else { 148 clnt_sa = (struct sockaddr *) 149 malloc(sizeof (struct sockaddr_storage)); 150 memcpy(clnt_sa, clnt, clnt->sa_len); 151 } 152 153 if (getifaddrs(&ifp) < 0) { 154 free(serv_nbp); 155 free(clnt_sa); 156 if (clnt_nbp != NULL) 157 free(clnt_nbp); 158 return 0; 159 } 160 161 /* 162 * Loop through all interfaces. For each interface, see if the 163 * network portion of its address is equal to that of the client. 164 * If so, we have found the interface that we want to use. 165 */ 166 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 167 if (ifap->ifa_addr->sa_family != clnt->sa_family || 168 !(ifap->ifa_flags & IFF_UP)) 169 continue; 170 171 switch (clnt->sa_family) { 172 case AF_INET: 173 /* 174 * realsin: address that recvfrom gave us. 175 * ifsin: address of interface being examined. 176 * clntsin: address that client want us to contact 177 * it on 178 * servsin: local address of RPC service. 179 * sinmask: netmask of this interface 180 * newsin: initially a copy of clntsin, eventually 181 * the merged address 182 */ 183 servsin = (struct sockaddr_in *)serv_sa; 184 clntsin = (struct sockaddr_in *)clnt_sa; 185 sinmask = (struct sockaddr_in *)ifap->ifa_netmask; 186 newsin = (struct sockaddr_in *)&ss; 187 ifsin = (struct sockaddr_in *)ifap->ifa_addr; 188 if (!bitmaskcmp(&ifsin->sin_addr, &clntsin->sin_addr, 189 &sinmask->sin_addr, sizeof (struct in_addr))) { 190 goto found; 191 } 192 break; 193 #ifdef INET6 194 case AF_INET6: 195 /* 196 * realsin6: address that recvfrom gave us. 197 * ifsin6: address of interface being examined. 198 * clntsin6: address that client want us to contact 199 * it on 200 * servsin6: local address of RPC service. 201 * sin6mask: netmask of this interface 202 * newsin6: initially a copy of clntsin, eventually 203 * the merged address 204 * 205 * For v6 link local addresses, if the client contacted 206 * us via a link-local address, and wants us to reply 207 * to one, use the scope id to see which one. 208 */ 209 realsin6 = (struct sockaddr_in6 *)clnt; 210 ifsin6 = (struct sockaddr_in6 *)ifap->ifa_addr; 211 inet6_getscopeid(ifsin6, 1); 212 clntsin6 = (struct sockaddr_in6 *)clnt_sa; 213 servsin6 = (struct sockaddr_in6 *)serv_sa; 214 sin6mask = (struct sockaddr_in6 *)ifap->ifa_netmask; 215 newsin6 = (struct sockaddr_in6 *)&ss; 216 if (IN6_IS_ADDR_LINKLOCAL(&ifsin6->sin6_addr) && 217 IN6_IS_ADDR_LINKLOCAL(&realsin6->sin6_addr) && 218 IN6_IS_ADDR_LINKLOCAL(&clntsin6->sin6_addr)) { 219 if (ifsin6->sin6_scope_id != 220 realsin6->sin6_scope_id) 221 continue; 222 goto found; 223 } 224 if (!bitmaskcmp(&ifsin6->sin6_addr, 225 &clntsin6->sin6_addr, &sin6mask->sin6_addr, 226 sizeof (struct in6_addr))) 227 goto found; 228 break; 229 #endif 230 default: 231 goto freeit; 232 } 233 } 234 /* 235 * Didn't find anything. Get the first possibly useful interface, 236 * preferring "normal" interfaces to point-to-point and loopback 237 * ones. 238 */ 239 bestif = NULL; 240 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 241 if (ifap->ifa_addr->sa_family != clnt->sa_family || 242 !(ifap->ifa_flags & IFF_UP)) 243 continue; 244 if (!(ifap->ifa_flags & IFF_LOOPBACK) && 245 !(ifap->ifa_flags & IFF_POINTOPOINT)) { 246 bestif = ifap; 247 break; 248 } 249 if (bestif == NULL) 250 bestif = ifap; 251 else if ((bestif->ifa_flags & IFF_LOOPBACK) && 252 !(ifap->ifa_flags & IFF_LOOPBACK)) 253 bestif = ifap; 254 } 255 ifap = bestif; 256 found: 257 switch (clnt->sa_family) { 258 case AF_INET: 259 memcpy(newsin, ifap->ifa_addr, clnt_sa->sa_len); 260 newsin->sin_port = servsin->sin_port; 261 tbuf.len = clnt_sa->sa_len; 262 tbuf.maxlen = sizeof (struct sockaddr_storage); 263 tbuf.buf = newsin; 264 break; 265 #ifdef INET6 266 case AF_INET6: 267 assert(newsin6); 268 memcpy(newsin6, ifsin6, clnt_sa->sa_len); 269 newsin6->sin6_port = servsin6->sin6_port; 270 tbuf.maxlen = sizeof (struct sockaddr_storage); 271 tbuf.len = clnt_sa->sa_len; 272 tbuf.buf = newsin6; 273 break; 274 #endif 275 default: 276 goto freeit; 277 } 278 if (ifap != NULL) 279 ret = taddr2uaddr(nconf, &tbuf); 280 freeit: 281 freenetconfigent(nconf); 282 free(serv_sa); 283 free(serv_nbp); 284 if (clnt_sa != NULL) 285 free(clnt_sa); 286 if (clnt_nbp != NULL) 287 free(clnt_nbp); 288 freeifaddrs(ifp); 289 290 #ifdef RPCBIND_DEBUG 291 if (debugging) 292 fprintf(stderr, "addrmerge: returning %s\n", ret); 293 #endif 294 return ret; 295 } 296 297 void 298 network_init() 299 { 300 #ifdef INET6 301 struct ifaddrs *ifap, *ifp; 302 struct ipv6_mreq mreq6; 303 unsigned int ifindex; 304 int s; 305 #endif 306 int ecode; 307 struct addrinfo hints, *res; 308 309 memset(&hints, 0, sizeof hints); 310 hints.ai_family = AF_INET; 311 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 312 if (debugging) 313 fprintf(stderr, "can't get local ip4 address: %s\n", 314 gai_strerror(ecode)); 315 } else { 316 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 317 if (local_in4 == NULL) { 318 if (debugging) 319 fprintf(stderr, "can't alloc local ip4 addr\n"); 320 } 321 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 322 } 323 324 #ifdef INET6 325 hints.ai_family = AF_INET6; 326 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 327 if (debugging) 328 fprintf(stderr, "can't get local ip6 address: %s\n", 329 gai_strerror(ecode)); 330 } else { 331 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 332 if (local_in6 == NULL) { 333 if (debugging) 334 fprintf(stderr, "can't alloc local ip6 addr\n"); 335 } 336 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 337 } 338 339 /* 340 * Now join the RPC ipv6 multicast group on all interfaces. 341 */ 342 if (getifaddrs(&ifp) < 0) 343 return; 344 345 mreq6.ipv6mr_interface = 0; 346 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 347 348 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 349 350 /* 351 * Loop through all interfaces. For each interface, see if the 352 * network portion of its address is equal to that of the client. 353 * If so, we have found the interface that we want to use. 354 */ 355 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 356 if (ifap->ifa_addr->sa_family != AF_INET6 || 357 !(ifap->ifa_flags & IFF_MULTICAST)) 358 continue; 359 ifindex = if_nametoindex(ifap->ifa_name); 360 if (ifindex == mreq6.ipv6mr_interface) 361 /* 362 * Already did this one. 363 */ 364 continue; 365 mreq6.ipv6mr_interface = ifindex; 366 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 367 sizeof mreq6) < 0) 368 if (debugging) 369 warn("setsockopt v6 multicast"); 370 } 371 freeifaddrs(ifp); 372 #endif 373 374 /* close(s); */ 375 } 376 377 struct sockaddr * 378 local_sa(int af) 379 { 380 switch (af) { 381 case AF_INET: 382 return (struct sockaddr *)local_in4; 383 #ifdef INET6 384 case AF_INET6: 385 return (struct sockaddr *)local_in6; 386 #endif 387 default: 388 return NULL; 389 } 390 } 391