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(void *, void *, void *, int); 74 #ifdef INET6 75 static void in6_fillscopeid(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. Returns 0 if the addresses 81 * match. 82 */ 83 static int 84 bitmaskcmp(void *dst, void *src, void *mask, int bytelen) 85 { 86 int i; 87 u_int8_t *p1 = dst, *p2 = src, *netmask = mask; 88 89 for (i = 0; i < bytelen; i++) 90 if ((p1[i] & netmask[i]) != (p2[i] & netmask[i])) 91 return (1); 92 return (0); 93 } 94 95 /* 96 * Similar to code in ifconfig.c. Fill in the scope ID for link-local 97 * addresses returned by getifaddrs(). 98 */ 99 #ifdef INET6 100 static void 101 in6_fillscopeid(struct sockaddr_in6 *sin6) 102 { 103 u_int16_t ifindex; 104 105 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 106 ifindex = ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]); 107 if (sin6->sin6_scope_id == 0 && ifindex != 0) { 108 sin6->sin6_scope_id = ifindex; 109 *(u_int16_t *)&sin6->sin6_addr.s6_addr[2] = 0; 110 } 111 } 112 } 113 #endif 114 115 /* 116 * Find a server address that can be used by `caller' to contact 117 * the local service specified by `serv_uaddr'. If `clnt_uaddr' is 118 * non-NULL, it is used instead of `caller' as a hint suggesting 119 * the best address (e.g. the `r_addr' field of an rpc, which 120 * contains the rpcbind server address that the caller used). 121 * 122 * Returns the best server address as a malloc'd "universal address" 123 * string which should be freed by the caller. On error, returns NULL. 124 */ 125 char * 126 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr, 127 char *netid) 128 { 129 struct ifaddrs *ifap, *ifp = NULL, *bestif; 130 struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf; 131 struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa; 132 struct sockaddr_storage ss; 133 struct netconfig *nconf; 134 char *caller_uaddr = NULL, *hint_uaddr = NULL; 135 char *ret = NULL; 136 137 #ifdef ND_DEBUG 138 if (debugging) 139 fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr, 140 clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid); 141 #endif 142 caller_sa = caller->buf; 143 if ((nconf = rpcbind_get_conf(netid)) == NULL) 144 goto freeit; 145 if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL) 146 goto freeit; 147 148 /* 149 * Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its 150 * address family is different from that of the caller. 151 */ 152 hint_sa = NULL; 153 if (clnt_uaddr != NULL) { 154 hint_uaddr = clnt_uaddr; 155 if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL) 156 goto freeit; 157 hint_sa = hint_nbp->buf; 158 } 159 if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) { 160 hint_uaddr = caller_uaddr; 161 hint_sa = caller->buf; 162 } 163 164 #ifdef ND_DEBUG 165 if (debugging) 166 fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr); 167 #endif 168 /* Local caller, just return the server address. */ 169 if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 || 170 strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') { 171 ret = strdup(serv_uaddr); 172 goto freeit; 173 } 174 175 if (getifaddrs(&ifp) < 0) 176 goto freeit; 177 178 /* 179 * Loop through all interfaces. For each interface, see if the 180 * network portion of its address is equal to that of the client. 181 * If so, we have found the interface that we want to use. 182 */ 183 bestif = NULL; 184 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 185 ifsa = ifap->ifa_addr; 186 ifmasksa = ifap->ifa_netmask; 187 188 if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family || 189 !(ifap->ifa_flags & IFF_UP)) 190 continue; 191 192 switch (hint_sa->sa_family) { 193 case AF_INET: 194 /* 195 * If the hint address matches this interface 196 * address/netmask, then we're done. 197 */ 198 if (!bitmaskcmp(&SA2SINADDR(ifsa), 199 &SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa), 200 sizeof(struct in_addr))) { 201 bestif = ifap; 202 goto found; 203 } 204 break; 205 #ifdef INET6 206 case AF_INET6: 207 /* 208 * For v6 link local addresses, if the caller is on 209 * a link-local address then use the scope id to see 210 * which one. 211 */ 212 in6_fillscopeid(SA2SIN6(ifsa)); 213 if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) && 214 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && 215 IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) { 216 if (SA2SIN6(ifsa)->sin6_scope_id == 217 SA2SIN6(caller_sa)->sin6_scope_id) { 218 bestif = ifap; 219 goto found; 220 } 221 } else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa), 222 &SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa), 223 sizeof(struct in6_addr))) { 224 bestif = ifap; 225 goto found; 226 } 227 break; 228 #endif 229 default: 230 continue; 231 } 232 233 /* 234 * Remember the first possibly useful interface, preferring 235 * "normal" to point-to-point and loopback ones. 236 */ 237 if (bestif == NULL || 238 (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) && 239 (bestif->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)))) 240 bestif = ifap; 241 } 242 if (bestif == NULL) 243 goto freeit; 244 245 found: 246 /* 247 * Construct the new address using the the address from 248 * `bestif', and the port number from `serv_uaddr'. 249 */ 250 serv_nbp = uaddr2taddr(nconf, serv_uaddr); 251 if (serv_nbp == NULL) 252 goto freeit; 253 serv_sa = serv_nbp->buf; 254 255 memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len); 256 switch (ss.ss_family) { 257 case AF_INET: 258 SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port; 259 break; 260 #ifdef INET6 261 case AF_INET6: 262 SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port; 263 break; 264 #endif 265 } 266 tbuf.len = ss.ss_len; 267 tbuf.maxlen = sizeof(ss); 268 tbuf.buf = &ss; 269 ret = taddr2uaddr(nconf, &tbuf); 270 271 freeit: 272 if (caller_uaddr != NULL) 273 free(caller_uaddr); 274 if (hint_nbp != NULL) { 275 free(hint_nbp->buf); 276 free(hint_nbp); 277 } 278 if (serv_nbp != NULL) { 279 free(serv_nbp->buf); 280 free(serv_nbp); 281 } 282 if (ifp != NULL) 283 freeifaddrs(ifp); 284 285 #ifdef ND_DEBUG 286 if (debugging) 287 fprintf(stderr, "addrmerge: returning %s\n", ret); 288 #endif 289 return ret; 290 } 291 292 void 293 network_init() 294 { 295 #ifdef INET6 296 struct ifaddrs *ifap, *ifp; 297 struct ipv6_mreq mreq6; 298 unsigned int ifindex; 299 int s; 300 #endif 301 int ecode; 302 struct addrinfo hints, *res; 303 304 memset(&hints, 0, sizeof hints); 305 hints.ai_family = AF_INET; 306 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 307 if (debugging) 308 fprintf(stderr, "can't get local ip4 address: %s\n", 309 gai_strerror(ecode)); 310 } else { 311 local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4); 312 if (local_in4 == NULL) { 313 if (debugging) 314 fprintf(stderr, "can't alloc local ip4 addr\n"); 315 } 316 memcpy(local_in4, res->ai_addr, sizeof *local_in4); 317 } 318 319 #ifdef INET6 320 hints.ai_family = AF_INET6; 321 if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) { 322 if (debugging) 323 fprintf(stderr, "can't get local ip6 address: %s\n", 324 gai_strerror(ecode)); 325 } else { 326 local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6); 327 if (local_in6 == NULL) { 328 if (debugging) 329 fprintf(stderr, "can't alloc local ip6 addr\n"); 330 } 331 memcpy(local_in6, res->ai_addr, sizeof *local_in6); 332 } 333 334 /* 335 * Now join the RPC ipv6 multicast group on all interfaces. 336 */ 337 if (getifaddrs(&ifp) < 0) 338 return; 339 340 mreq6.ipv6mr_interface = 0; 341 inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr); 342 343 s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); 344 345 /* 346 * Loop through all interfaces. For each IPv6 multicast-capable 347 * interface, join the RPC multicast group on that interface. 348 */ 349 for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) { 350 if (ifap->ifa_addr->sa_family != AF_INET6 || 351 !(ifap->ifa_flags & IFF_MULTICAST)) 352 continue; 353 ifindex = if_nametoindex(ifap->ifa_name); 354 if (ifindex == mreq6.ipv6mr_interface) 355 /* 356 * Already did this one. 357 */ 358 continue; 359 mreq6.ipv6mr_interface = ifindex; 360 if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6, 361 sizeof mreq6) < 0) 362 if (debugging) 363 perror("setsockopt v6 multicast"); 364 } 365 #endif 366 367 /* close(s); */ 368 } 369 370 struct sockaddr * 371 local_sa(int af) 372 { 373 switch (af) { 374 case AF_INET: 375 return (struct sockaddr *)local_in4; 376 #ifdef INET6 377 case AF_INET6: 378 return (struct sockaddr *)local_in6; 379 #endif 380 default: 381 return NULL; 382 } 383 } 384