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 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the NetBSD 24 * Foundation, Inc. and its contributors. 25 * 4. Neither the name of The NetBSD Foundation nor the names of its 26 * contributors may be used to endorse or promote products derived 27 * from this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 30 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 31 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 32 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 33 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 34 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 35 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 39 * POSSIBILITY OF SUCH DAMAGE. 40 */ 41 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #include <sys/queue.h> 45 #include <net/if.h> 46 #include <netinet/in.h> 47 #include <ifaddrs.h> 48 #include <sys/poll.h> 49 #include <rpc/rpc.h> 50 #include <errno.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 #include <netdb.h> 55 #include <netconfig.h> 56 #include <stdio.h> 57 #include <arpa/inet.h> 58 59 #include "rpcbind.h" 60 61 #define SA2SIN(sa) ((struct sockaddr_in *)(sa)) 62 #define SA2SINADDR(sa) (SA2SIN(sa)->sin_addr) 63 #ifdef INET6 64 #define SA2SIN6(sa) ((struct sockaddr_in6 *)(sa)) 65 #define SA2SIN6ADDR(sa) (SA2SIN6(sa)->sin6_addr) 66 #endif 67 68 static struct sockaddr_in *local_in4; 69 #ifdef INET6 70 static struct sockaddr_in6 *local_in6; 71 #endif 72 73 static int bitmaskcmp __P((void *, void *, void *, int)); 74 #ifdef INET6 75 static void in6_fillscopeid __P((struct sockaddr_in6 *)); 76 #endif 77 78 /* 79 * For all bits set in "mask", compare the corresponding bits in 80 * "dst" and "src", and see if they match. 81 */ 82 static int 83 bitmaskcmp(void *dst, void *src, void *mask, int bytelen) 84 { 85 int i, j; 86 u_int8_t *p1 = dst, *p2 = src, *netmask = mask; 87 u_int8_t bitmask; 88 89 for (i = 0; i < bytelen; i++) { 90 for (j = 0; j < 8; j++) { 91 bitmask = 1 << j; 92 if (!(netmask[i] & bitmask)) 93 continue; 94 if ((p1[i] & bitmask) != (p2[i] & bitmask)) 95 return 1; 96 } 97 } 98 99 return 0; 100 } 101 102 /* 103 * Taken from ifconfig.c 104 */ 105 #ifdef INET6 106 static void 107 in6_fillscopeid(struct sockaddr_in6 *sin6) 108 { 109 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 110 sin6->sin6_scope_id = 111 ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]); 112 sin6->sin6_addr.s6_addr[2] = sin6->sin6_addr.s6_addr[3] = 0; 113 } 114 } 115 #endif 116 117 /* 118 * Find a server address that can be used by `caller' to contact 119 * the local service specified by `serv_uaddr'. If `clnt_uaddr' is 120 * non-NULL, it is used instead of `caller' as a hint suggesting 121 * the best address (e.g. the `r_addr' field of an rpc, which 122 * contains the rpcbind server address that the caller used). 123 * 124 * Returns the best server address as a malloc'd "universal address" 125 * string which should be freed by the caller. On error, returns NULL. 126 */ 127 char * 128 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr, 129 char *netid) 130 { 131 struct ifaddrs *ifap, *ifp = NULL, *bestif; 132 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf; 133 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa; 134 struct sockaddr_storage ss; 135 struct netconfig *nconf; 136 char *caller_uaddr = NULL, *hint_uaddr = NULL; 137 char *ret = NULL; 138 139 #ifdef ND_DEBUG 140 if (debugging) 141 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 142 clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid); 143 #endif 144 caller_sa = caller->buf; 145 if ((nconf = rpcbind_get_conf(netid)) == NULL) 146 goto freeit; 147 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL) 148 goto freeit; 149 150 /* 151 * Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its 152 * address family is different from that of the caller. 153 */ 154 hint_sa = NULL; 155 if (clnt_uaddr != NULL) { 156 hint_uaddr = clnt_uaddr; 157 if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL) 158 goto freeit; 159 hint_sa = hint_nbp->buf; 160 } 161 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) { 162 hint_uaddr = caller_uaddr; 163 hint_sa = caller->buf; 164 } 165 166 #ifdef ND_DEBUG 167 if (debugging) 168 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr); 169 #endif 170 /* Local caller, just return the server address. */ 171 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 || 172 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') { 173 ret = strdup(serv_uaddr); 174 goto freeit; 175 } 176 177 if (getifaddrs(&ifp) < 0) 178 goto freeit; 179 180 /* 181 * Loop through all interfaces. For each interface, see if the 182 * network portion of its address is equal to that of the client. 183 * If so, we have found the interface that we want to use. 184 */ 185 bestif = NULL; 186 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 187 ifsa = ifap->ifa_addr; 188 ifmasksa = ifap->ifa_netmask; 189 190 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family || 191 !(ifap->ifa_flags & IFF_UP)) 192 continue; 193 194 switch (hint_sa->sa_family) { 195 case AF_INET: 196 /* 197 * If the hint address matches this interface 198 * address/netmask, then we're done. 199 */ 200 if (!bitmaskcmp(&SA2SINADDR(ifsa), 201 &SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa), 202 sizeof(struct in_addr))) { 203 bestif = ifap; 204 goto found; 205 } 206 break; 207 #ifdef INET6 208 case AF_INET6: 209 /* 210 * For v6 link local addresses, if the caller is on 211 * a link-local address then use the scope id to see 212 * which one. 213 */ 214 in6_fillscopeid(SA2SIN6(ifsa)); 215 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) && 216 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && 217 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) { 218 if (SA2SIN6(ifsa)->sin6_scope_id == 219 SA2SIN6(caller_sa)->sin6_scope_id) { 220 bestif = ifap; 221 goto found; 222 } 223 } else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa), 224 &SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa), 225 sizeof(struct in6_addr))) { 226 bestif = ifap; 227 goto found; 228 } 229 break; 230 #endif 231 default: 232 continue; 233 } 234 235 /* 236 * Remember the first possibly useful interface, preferring 237 * "normal" to point-to-point and loopback ones. 238 */ 239 if (bestif == NULL || 240 (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) && 241 (bestif->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)))) 242 bestif = ifap; 243 } 244 if (bestif == NULL) 245 goto freeit; 246 247 found: 248 /* 249 * Construct the new address using the the address from 250 * `bestif', and the port number from `serv_uaddr'. 251 */ 252 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 253 if (serv_nbp == NULL) 254 goto freeit; 255 serv_sa = serv_nbp->buf; 256 257 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len); 258 switch (ss.ss_family) { 259 case AF_INET: 260 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port; 261 break; 262 #ifdef INET6 263 case AF_INET6: 264 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port; 265 break; 266 #endif 267 } 268 tbuf.len = ss.ss_len; 269 tbuf.maxlen = sizeof(ss); 270 tbuf.buf = &ss; 271 ret = taddr2uaddr(nconf, &tbuf); 272 273 freeit: 274 if (caller_uaddr != NULL) 275 free(caller_uaddr); 276 if (hint_nbp != NULL) { 277 free(hint_nbp->buf); 278 free(hint_nbp); 279 } 280 if (serv_nbp != NULL) { 281 free(serv_nbp->buf); 282 free(serv_nbp); 283 } 284 if (ifp != NULL) 285 freeifaddrs(ifp); 286 287 #ifdef ND_DEBUG 288 if (debugging) 289 fprintf(stderr, "addrmerge: returning %s\n", ret); 290 #endif 291 return ret; 292 } 293 294 void 295 network_init() 296 { 297 #ifdef INET6 298 struct ifaddrs *ifap, *ifp; 299 struct ipv6_mreq mreq6; 300 int ifindex, s; 301 #endif 302 int ecode; 303 struct addrinfo hints, *res; 304 305 memset(&hints, 0, sizeof hints); 306 hints.ai_family = AF_INET; 307 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 308 if (debugging) 309 fprintf(stderr, "can't get local ip4 address: %s\n", 310 gai_strerror(ecode)); 311 } else { 312 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 313 if (local_in4 == NULL) { 314 if (debugging) 315 fprintf(stderr, "can't alloc local ip4 addr\n"); 316 } 317 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 318 } 319 320 #ifdef INET6 321 hints.ai_family = AF_INET6; 322 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 323 if (debugging) 324 fprintf(stderr, "can't get local ip6 address: %s\n", 325 gai_strerror(ecode)); 326 } else { 327 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 328 if (local_in6 == NULL) { 329 if (debugging) 330 fprintf(stderr, "can't alloc local ip6 addr\n"); 331 } 332 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 333 } 334 335 /* 336 * Now join the RPC ipv6 multicast group on all interfaces. 337 */ 338 if (getifaddrs(&ifp) < 0) 339 return; 340 341 mreq6.ipv6mr_interface = 0; 342 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 343 344 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 345 346 /* 347 * Loop through all interfaces. For each interface, see if the 348 * network portion of its address is equal to that of the client. 349 * If so, we have found the interface that we want to use. 350 */ 351 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 352 if (ifap->ifa_addr->sa_family != AF_INET6 || 353 !(ifap->ifa_flags & IFF_MULTICAST)) 354 continue; 355 ifindex = if_nametoindex(ifap->ifa_name); 356 if (ifindex == mreq6.ipv6mr_interface) 357 /* 358 * Already did this one. 359 */ 360 continue; 361 mreq6.ipv6mr_interface = ifindex; 362 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 363 sizeof mreq6) < 0) 364 if (debugging) 365 perror("setsockopt v6 multicast"); 366 } 367 #endif 368 369 /* close(s); */ 370 } 371 372 struct sockaddr * 373 local_sa(int af) 374 { 375 switch (af) { 376 case AF_INET: 377 return (struct sockaddr *)local_in4; 378 #ifdef INET6 379 case AF_INET6: 380 return (struct sockaddr *)local_in6; 381 #endif 382 default: 383 return NULL; 384 } 385 } 386