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