1/* 2 * $NetBSD: util.c,v 1.4 2000/08/03 00:04:30 fvdl Exp $ 3 */ 4 5/*- 6 * SPDX-License-Identifier: BSD-2-Clause 7 * 8 * Copyright (c) 2000 The NetBSD Foundation, Inc. 9 * All rights reserved. 10 * 11 * This code is derived from software contributed to The NetBSD Foundation 12 * by Frank van der Linden. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36#include <sys/types.h> 37#include <sys/socket.h> 38#include <sys/queue.h> 39#include <net/if.h> 40#include <netinet/in.h> 41#include <ifaddrs.h> 42#include <sys/poll.h> 43#include <rpc/rpc.h> 44#include <stdlib.h> 45#include <string.h> 46#include <netdb.h> 47#include <netconfig.h> 48#include <stdio.h> 49#include <arpa/inet.h> 50 51#include "rpcbind.h" 52 53static struct sockaddr_in *local_in4; 54#ifdef INET6 55static struct sockaddr_in6 *local_in6; 56#endif 57 58static int bitmaskcmp(struct sockaddr *, struct sockaddr *, struct sockaddr *); 59 60/* 61 * For all bits set in "mask", compare the corresponding bits in 62 * "dst" and "src", and see if they match. Returns 0 if the addresses 63 * match. 64 */ 65static int 66bitmaskcmp(struct sockaddr *dst, struct sockaddr *src, struct sockaddr *mask) 67{ 68 int i; 69 u_int8_t *p1, *p2, *netmask; 70 int bytelen; 71 72 if (dst->sa_family != src->sa_family || 73 dst->sa_family != mask->sa_family) 74 return (1); 75 76 switch (dst->sa_family) { 77 case AF_INET: 78 p1 = (uint8_t*) &SA2SINADDR(dst); 79 p2 = (uint8_t*) &SA2SINADDR(src); 80 netmask = (uint8_t*) &SA2SINADDR(mask); 81 bytelen = sizeof(struct in_addr); 82 break; 83#ifdef INET6 84 case AF_INET6: 85 p1 = (uint8_t*) &SA2SIN6ADDR(dst); 86 p2 = (uint8_t*) &SA2SIN6ADDR(src); 87 netmask = (uint8_t*) &SA2SIN6ADDR(mask); 88 bytelen = sizeof(struct in6_addr); 89 break; 90#endif 91 default: 92 return (1); 93 } 94 95 for (i = 0; i < bytelen; i++) 96 if ((p1[i] & netmask[i]) != (p2[i] & netmask[i])) 97 return (1); 98 return (0); 99} 100 101/* 102 * Find a server address that can be used by `caller' to contact 103 * the local service specified by `serv_uaddr'. If `contct_uaddr' is 104 * non-NULL, it is used instead of `caller' as a hint suggesting 105 * the best address (e.g. the `r_addr' field of an rpc, which 106 * contains the rpcbind server address that the caller used). 107 * 108 * Returns the best server address as a malloc'd "universal address" 109 * string which should be freed by the caller. On error, returns NULL. 110 */ 111char * 112addrmerge(struct netbuf *caller, const char *serv_uaddr, 113 const char *contct_uaddr, const char *netid) 114{ 115 struct ifaddrs *ifap, *ifp = NULL, *bestif; 116 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf; 117 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa; 118 struct sockaddr_storage ss; 119 struct netconfig *nconf; 120 char *caller_uaddr = NULL; 121#ifdef ND_DEBUG 122 const char *hint_uaddr = NULL; 123#endif 124 char *ret = NULL; 125 int bestif_goodness; 126 127#ifdef ND_DEBUG 128 if (debugging) 129 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 130 contct_uaddr == NULL ? "NULL" : contct_uaddr, netid); 131#endif 132 caller_sa = caller->buf; 133 if ((nconf = rpcbind_get_conf(netid)) == NULL) 134 goto freeit; 135 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL) 136 goto freeit; 137 138 /* 139 * Use `contct_uaddr' as the hint if non-NULL, but ignore it if its 140 * address family is different from that of the caller. 141 */ 142 hint_sa = NULL; 143 if (contct_uaddr != NULL) { 144#ifdef ND_DEBUG 145 hint_uaddr = contct_uaddr; 146#endif 147 if ((hint_nbp = uaddr2taddr(nconf, contct_uaddr)) == NULL) 148 goto freeit; 149 hint_sa = hint_nbp->buf; 150 } 151 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) { 152#ifdef ND_DEBUG 153 hint_uaddr = caller_uaddr; 154#endif 155 hint_sa = caller->buf; 156 } 157 158#ifdef ND_DEBUG 159 if (debugging) 160 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr); 161#endif 162 /* Local caller, just return the server address. */ 163 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 || 164 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') { 165 ret = strdup(serv_uaddr); 166 goto freeit; 167 } 168 169 if (getifaddrs(&ifp) < 0) 170 goto freeit; 171 172 /* 173 * Loop through all interface addresses. We are listening to an address 174 * if any of the following are true: 175 * a) It's a loopback address 176 * b) It was specified with the -h command line option 177 * c) There were no -h command line options. 178 * 179 * Among addresses on which we are listening, choose in order of 180 * preference an address that is: 181 * 182 * a) Equal to the hint 183 * b) A link local address with the same scope ID as the client's 184 * address, if the client's address is also link local 185 * c) An address on the same subnet as the client's address 186 * d) A non-localhost, non-p2p address 187 * e) Any usable address 188 */ 189 bestif = NULL; 190 bestif_goodness = 0; 191 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 192 ifsa = ifap->ifa_addr; 193 ifmasksa = ifap->ifa_netmask; 194 195 /* Skip addresses where we don't listen */ 196 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family || 197 !(ifap->ifa_flags & IFF_UP)) 198 continue; 199 200 if (!(ifap->ifa_flags & IFF_LOOPBACK) && !listen_addr(ifsa)) 201 continue; 202 203 if ((hint_sa->sa_family == AF_INET) && 204 ((((struct sockaddr_in*)hint_sa)->sin_addr.s_addr == 205 ((struct sockaddr_in*)ifsa)->sin_addr.s_addr))) { 206 const int goodness = 4; 207 208 bestif_goodness = goodness; 209 bestif = ifap; 210 goto found; 211 } 212#ifdef INET6 213 if ((hint_sa->sa_family == AF_INET6) && 214 (0 == memcmp(&((struct sockaddr_in6*)hint_sa)->sin6_addr, 215 &((struct sockaddr_in6*)ifsa)->sin6_addr, 216 sizeof(struct in6_addr))) && 217 (((struct sockaddr_in6*)hint_sa)->sin6_scope_id == 218 (((struct sockaddr_in6*)ifsa)->sin6_scope_id))) { 219 const int goodness = 4; 220 221 bestif_goodness = goodness; 222 bestif = ifap; 223 goto found; 224 } 225 if (hint_sa->sa_family == AF_INET6) { 226 /* 227 * For v6 link local addresses, if the caller is on 228 * a link-local address then use the scope id to see 229 * which one. 230 */ 231 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa))) { 232 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && 233 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa)) && 234 (SA2SIN6(ifsa)->sin6_scope_id == 235 SA2SIN6(caller_sa)->sin6_scope_id)) { 236 const int goodness = 3; 237 238 if (bestif_goodness < goodness) { 239 bestif = ifap; 240 bestif_goodness = goodness; 241 } 242 } else { 243 continue; 244 } 245 } 246 } 247#endif /* INET6 */ 248 if (0 == bitmaskcmp(hint_sa, ifsa, ifmasksa)) { 249 const int goodness = 2; 250 251 if (bestif_goodness < goodness) { 252 bestif = ifap; 253 bestif_goodness = goodness; 254 } 255 } 256 if (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) { 257 const int goodness = 1; 258 259 if (bestif_goodness < goodness) { 260 bestif = ifap; 261 bestif_goodness = goodness; 262 } 263 } 264 if (bestif == NULL) 265 bestif = ifap; 266 } 267 if (bestif == NULL) 268 goto freeit; 269 270found: 271 /* 272 * Construct the new address using the address from 273 * `bestif', and the port number from `serv_uaddr'. 274 */ 275 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 276 if (serv_nbp == NULL) 277 goto freeit; 278 serv_sa = serv_nbp->buf; 279 280 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len); 281 switch (ss.ss_family) { 282 case AF_INET: 283 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port; 284 break; 285#ifdef INET6 286 case AF_INET6: 287 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port; 288 break; 289#endif 290 } 291 tbuf.len = ss.ss_len; 292 tbuf.maxlen = sizeof(ss); 293 tbuf.buf = &ss; 294 ret = taddr2uaddr(nconf, &tbuf); 295 296freeit: 297 free(caller_uaddr); 298 if (hint_nbp != NULL) { 299 free(hint_nbp->buf); 300 free(hint_nbp); 301 } 302 if (serv_nbp != NULL) { 303 free(serv_nbp->buf); 304 free(serv_nbp); 305 } 306 if (ifp != NULL) 307 freeifaddrs(ifp); 308 309#ifdef ND_DEBUG 310 if (debugging) 311 fprintf(stderr, "addrmerge: returning %s\n", ret); 312#endif 313 return ret; 314} 315 316void 317network_init(void) 318{ 319#ifdef INET6 320 struct ifaddrs *ifap, *ifp; 321 struct ipv6_mreq mreq6; 322 unsigned int ifindex; 323 int s; 324#endif 325 int ecode; 326 struct addrinfo hints, *res; 327 328 memset(&hints, 0, sizeof hints); 329 hints.ai_family = AF_INET; 330 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 331 if (debugging) 332 fprintf(stderr, "can't get local ip4 address: %s\n", 333 gai_strerror(ecode)); 334 } else { 335 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 336 if (local_in4 == NULL) { 337 if (debugging) 338 fprintf(stderr, "can't alloc local ip4 addr\n"); 339 exit(1); 340 } 341 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 342 freeaddrinfo(res); 343 } 344 345#ifdef INET6 346 hints.ai_family = AF_INET6; 347 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 348 if (debugging) 349 fprintf(stderr, "can't get local ip6 address: %s\n", 350 gai_strerror(ecode)); 351 } else { 352 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 353 if (local_in6 == NULL) { 354 if (debugging) 355 fprintf(stderr, "can't alloc local ip6 addr\n"); 356 exit(1); 357 } 358 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 359 freeaddrinfo(res); 360 } 361 362 /* 363 * Now join the RPC ipv6 multicast group on all interfaces. 364 */ 365 if (getifaddrs(&ifp) < 0) 366 return; 367 368 mreq6.ipv6mr_interface = 0; 369 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 370 371 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 372 if (s == -1) { 373 if (debugging) 374 fprintf(stderr, "couldn't create ip6 socket"); 375 goto done_inet6; 376 } 377 378 /* 379 * Loop through all interfaces. For each IPv6 multicast-capable 380 * interface, join the RPC multicast group on that interface. 381 */ 382 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 383 if (ifap->ifa_addr->sa_family != AF_INET6 || 384 !(ifap->ifa_flags & IFF_MULTICAST)) 385 continue; 386 ifindex = if_nametoindex(ifap->ifa_name); 387 if (ifindex == mreq6.ipv6mr_interface) 388 /* 389 * Already did this one. 390 */ 391 continue; 392 mreq6.ipv6mr_interface = ifindex; 393 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 394 sizeof mreq6) < 0) 395 if (debugging) 396 perror("setsockopt v6 multicast"); 397 } 398done_inet6: 399 freeifaddrs(ifp); 400#endif 401 402 /* close(s); */ 403} 404 405struct sockaddr * 406local_sa(int af) 407{ 408 switch (af) { 409 case AF_INET: 410 return (struct sockaddr *)local_in4; 411#ifdef INET6 412 case AF_INET6: 413 return (struct sockaddr *)local_in6; 414#endif 415 default: 416 return NULL; 417 } 418} 419