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 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 * 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 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 * 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